three malignant brain tumor (MBT) repeat found in Scm-like with four MBT domains protein 2 (SFMBT2); SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. SFMBT2 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  46 HFFTVGMKLETVNMCEPFYISPASVTKVFNNHFFQVTIDDLRPEPSKLSMLCHADSLGILPVQWCLKNGVSLTPPKGYSG 125
Cdd:cd20116     1 HSFTVGMKLEVVDPREPFHICPASVTKVFNNHYFQVTVDDLRPEASENSMLCHADSLGILPVQWCLKNGVNLTPPKGYSG 80

                          90
                  ....*....|...
gi 2462520368 126 QDFDWADYHKQHG 138
Cdd:cd20116    81 QDFDWADYQKQCG 93

SAM domain of Scm-like-4MBT1,2 proteins of Polycomb group; SAM (sterile alpha motif) domain of Scm-like-4MBT1,2 (Sex comb on midleg, Malignant Brain Tumor) subfamily proteins (also known as Sfmbt1,2 proteins) is a putative protein-protein interaction domain. Proteins of this subfamily are transcriptional regulators belonging to Polycomb group. The majority of them are multidomain proteins: in addition to the C-terminal SAM domain, they contain four MBT repeats and DUF5388 domain. The MBT repeats of the human sfmbt1 protein are responsible for association with the nuclear matrix and for selective binding of H3 histone N-terminal tails, while the exact function of the SAM domain is unclear.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368 558 EEEERLVLESNPLEWTVTDVVRFIKLTDCAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIERVKVAFY 637
Cdd:cd09581     1 EEEERLKLDSNPLFWSVDDVVRFIKSTDCAPLAKIFKDQEIDGQALLLLTLPTVQECMELKLGPAIKLCHHIERVKVAFY 80

                  ....*
gi 2462520368 638 AQYAN 642
Cdd:cd09581    81 EQFAN 85

malignant brain tumor (MBT) repeat; The MBT repeat is a protein module that recognizes methylated lysine residues on histones and are thought to affect a variety of chromatin processes, including transcription. It exists as tandem repeats and is found in a number of nuclear proteins such as Drosophila sex comb on midleg protein. In the human genome, there are at least 9 MBT repeat proteins, each containing two, three or four MBT repeats. MBT repeat proteins use a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine (monomethyllysine and/or dimethyllysine).

                          10        20
                  ....*....|....*....|....*....
gi 2462520368   1 MDPPSEIYPLKMASEWKCTLEKSLIDAAK 29
Cdd:cd20114    70 MEPPTEICDLKSASEWKEALEKSLAEAAN 98

three malignant brain tumor (MBT) repeat found in Scm-like with four MBT domains protein 2 (SFMBT2); SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. SFMBT2 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  46 HFFTVGMKLETVNMCEPFYISPASVTKVFNNHFFQVTIDDLRPEPSKLSMLCHADSLGILPVQWCLKNGVSLTPPKGYSG 125
Cdd:cd20116     1 HSFTVGMKLEVVDPREPFHICPASVTKVFNNHYFQVTVDDLRPEASENSMLCHADSLGILPVQWCLKNGVNLTPPKGYSG 80

                          90
                  ....*....|...
gi 2462520368 126 QDFDWADYHKQHG 138
Cdd:cd20116    81 QDFDWADYQKQCG 93

SAM domain of Scm-like-4MBT1,2 proteins of Polycomb group; SAM (sterile alpha motif) domain of Scm-like-4MBT1,2 (Sex comb on midleg, Malignant Brain Tumor) subfamily proteins (also known as Sfmbt1,2 proteins) is a putative protein-protein interaction domain. Proteins of this subfamily are transcriptional regulators belonging to Polycomb group. The majority of them are multidomain proteins: in addition to the C-terminal SAM domain, they contain four MBT repeats and DUF5388 domain. The MBT repeats of the human sfmbt1 protein are responsible for association with the nuclear matrix and for selective binding of H3 histone N-terminal tails, while the exact function of the SAM domain is unclear.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368 558 EEEERLVLESNPLEWTVTDVVRFIKLTDCAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIERVKVAFY 637
Cdd:cd09581     1 EEEERLKLDSNPLFWSVDDVVRFIKSTDCAPLAKIFKDQEIDGQALLLLTLPTVQECMELKLGPAIKLCHHIERVKVAFY 80

                  ....*
gi 2462520368 638 AQYAN 642
Cdd:cd09581    81 EQFAN 85

Present in Drosophila Scm, l(3)mbt, and vertebrate SCML2; Present in Drosophila Scm, l(3)mbt, and vertebrate SCML2. These proteins are involved in transcriptional regulation.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  132 DYHKQHGAQEAPPFCF--RNTSFSRGFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPvPEVIVDVESMDI 209
Cdd:smart00561   2 DYLEETGARAAPVELFkqPVDSPPNGFKVGMKLEAVDPRNPSLICVATVVEVKGYRLLLHFDGWDDK-YDFWCHADSPDI 80

                           90
                   ....*....|....*.
gi 2462520368  210 FPVGWCEANSYPLTAP 225
Cdd:smart00561  81 FPVGWCEKNGHPLQPP 96

mbt repeat; The function of this repeat is unknown, but is found in a number of nuclear proteins such as drosophila sex comb on midleg protein. The repeat is found in up to four copies as in Swiss:Q9UHJ3. The repeat contains a completely conserved glutamate at its amino terminus that may be important for function.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2462520368 160 MKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLqTPVPEVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:pfam02820   1 MKLEAVDPLNPSLICVATVVKVLGGRLRLRFDGW-DDSYDFWCHADSPDIHPVGWCEKNGHPLQPP 65

second malignant brain tumor (MBT) repeat found in Scm-like with four MBT domains protein 2 (SFMBT2); SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. SFMBT2 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the second MBT repeat that contains a partially conserved semi-aromatic cage.

                          10        20
                  ....*....|....*....|....*....
gi 2462520368   1 MDPPSEIYPLKMASEWKCTLEKSLIDAAK 29
Cdd:cd20114    70 MEPPTEICDLKSASEWKEALEKSLAEAAN 98

SAM domain (Sterile alpha motif); It has been suggested that SAM is an evolutionarily conserved protein binding domain that is involved in the regulation of numerous developmental processes in diverse eukaryotes. The SAM domain can potentially function as a protein interaction module through its ability to homo- and heterooligomerise with other SAM domains.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2462520368 571 EWTVTDVVRFIKLTDCAPLAKIFQEQDIDGQALLLLtlpTVQECMEL---KLGPAIKLCHQIERVK 633
Cdd:pfam00536   2 GWSVEDVGEWLESIGLGQYIDSFRAGYIDGDALLQL---TEDDLLKLgvtLLGHRKKILYAIQRLK 64

three malignant brain tumor (MBT) repeat found in Scm-like with four MBT domains protein 2 (SFMBT2); SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. SFMBT2 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  46 HFFTVGMKLETVNMCEPFYISPASVTKVFNNHFFQVTIDDLRPEPSKLSMLCHADSLGILPVQWCLKNGVSLTPPKGYSG 125
Cdd:cd20116     1 HSFTVGMKLEVVDPREPFHICPASVTKVFNNHYFQVTVDDLRPEASENSMLCHADSLGILPVQWCLKNGVNLTPPKGYSG 80

                          90
                  ....*....|...
gi 2462520368 126 QDFDWADYHKQHG 138
Cdd:cd20116    81 QDFDWADYQKQCG 93

SAM domain of Scm-like-4MBT1,2 proteins of Polycomb group; SAM (sterile alpha motif) domain of Scm-like-4MBT1,2 (Sex comb on midleg, Malignant Brain Tumor) subfamily proteins (also known as Sfmbt1,2 proteins) is a putative protein-protein interaction domain. Proteins of this subfamily are transcriptional regulators belonging to Polycomb group. The majority of them are multidomain proteins: in addition to the C-terminal SAM domain, they contain four MBT repeats and DUF5388 domain. The MBT repeats of the human sfmbt1 protein are responsible for association with the nuclear matrix and for selective binding of H3 histone N-terminal tails, while the exact function of the SAM domain is unclear.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368 558 EEEERLVLESNPLEWTVTDVVRFIKLTDCAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIERVKVAFY 637
Cdd:cd09581     1 EEEERLKLDSNPLFWSVDDVVRFIKSTDCAPLAKIFKDQEIDGQALLLLTLPTVQECMELKLGPAIKLCHHIERVKVAFY 80

                  ....*
gi 2462520368 638 AQYAN 642
Cdd:cd09581    81 EQFAN 85

third malignant brain tumor (MBT) repeat found in the Scm-like with four MBT domains protein (SFMBT) family; The SFMBT family includes SFMBT1 and SFMBT2. SFMBT1, also called renal ubiquitous protein 1, is a transcriptional repressor protein that selectively binds the N-terminal tail of histone H3 and functions as a chromatin reader in regulating epigenetic silencing and the myogenic gene program. It mediates the recruitment of corepressor complexes to target genes, followed by chromatin compaction and repression of transcription. SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. Members of this family contain four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  48 FTVGMKLETVNMCEPFYISPASVTKVFNNHFFQVTIDDLRPEPSK-LSMLCHADSLGILPVQWCLKNGVSLTPPKGYSGQ 126
Cdd:cd20095     1 FKVGMKLEALHPKNPSTICPATVTKVFNEYYFLVEIDDLRPEESEkITFVCHANSPGIFPVGWCAKNGLRLTPPPGYPKS 80

                          90
                  ....*....|..
gi 2462520368 127 DFDWADYHKQHG 138
Cdd:cd20095    81 EFDWDSYLKLCG 92

fourth malignant brain tumor (MBT) repeat found in the Scm-like with four MBT domains protein (SFMBT) family; The SFMBT family includes SFMBT1 and SFMBT2. SFMBT1, also called renal ubiquitous protein 1, is a transcriptional repressor protein that selectively binds the N-terminal tail of histone H3 and functions as a chromatin reader in regulating epigenetic silencing and the myogenic gene program. It mediates the recruitment of corepressor complexes to target genes, followed by chromatin compaction and repression of transcription. SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. Members of this family contain four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the fourth MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2462520368 156 FTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVPEVIVDVESMDIFPVGWCEANSYPLTAPHKT 228
Cdd:cd20096     1 FERGMKLEAVNPENPNQICVATITKVVGPLLWLHLDSEKKLSPNIIVDVESTDIFPVGWCESNGYPLVTPRKY 73

fourth malignant brain tumor (MBT) repeat found in Scm-like with four MBT domains protein 1 (SFMBT1); SFMBT1, also called renal ubiquitous protein 1, is a transcriptional repressor protein that selectively binds the N-terminal tail of histone H3 and functions as a chromatin reader in regulating epigenetic silencing and the myogenic gene program. It mediates the recruitment of corepressor complexes to target genes, followed by chromatin compaction and repression of transcription. SFMBT1 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the fourth MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368 155 GFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVPEVIVDVESMDIFPVGWCEANSYPLTAPHKTVSQKKR 234
Cdd:cd20117     2 CFKENMKLEAVNPICPEEICVATVTKVKGSYLWLQLEGSKKPIPECIVHVESMDIFPVGWCETNGYPLLHPRKARVNKQR 81

                  ....*....
gi 2462520368 235 KIAVVQPEK 243
Cdd:cd20117    82 KIAVVQPEK 90

SAM domain of Polycomb group; SAM (sterile alpha motif) domain of Polycomb group is a protein-protein interaction domain. The Polycomb group includes transcriptional repressors which are involved in the regulation of some key regulatory genes during development in many organisms. They are best known for silencing Hox (Homeobox) genes. Polycomb proteins work together in large multimeric and chromatin-associated complexes. They organize chromatin of the target genes and maintain repressed states during many cell divisions. Polycomb proteins are classified based on their common function, but not on conserved domains and/or motifs; however many Polycomb proteins (members of PRC1 class complex) contain SAM domains which are more similar to each other inside of the Polycomb group than to SAM domains outside of it. Most information about structure and function of Polycomb SAM domains comes from studies of Ph (Polyhomeotic) and Scm (Sex comb on midleg) proteins. Polycomb SAM domains usually can be found at the C-terminus of the proteins. Some members of this group contain, in addition to the SAM domain, MTB repeats, Zn finger, and/or DUF3588 domains. Polycomb SAM domains can form homo- and/or heterooligomers through ML and EH surfaces. SAM/SAM oligomers apparently play a role in transcriptional repression through polymerization along the chromosome. Polycomb proteins are known to be highly expressed in some cells years before their cancer pathology; thus they are attractive markers for early cancer therapy.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2462520368 569 PLEWTVTDVVRFIKLTD-CAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIER 631
Cdd:cd09509     1 PSKWSVDDVAQFIKSLDgCAEYAEVFREQEIDGQALLLLTEDDLLKGMGLKLGPALKIYNHIVK 64

malignant brain tumor (MBT) repeat; The MBT repeat is a protein module that recognizes methylated lysine residues on histones and are thought to affect a variety of chromatin processes, including transcription. It exists as tandem repeats and is found in a number of nuclear proteins such as Drosophila sex comb on midleg protein. In the human genome, there are at least 9 MBT repeat proteins, each containing two, three or four MBT repeats. MBT repeat proteins use a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine (monomethyllysine and/or dimethyllysine).

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2462520368 156 FTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVPEVIVDVESMDIFPVGWCE 216
Cdd:cd20088     1 FKVGMKLEAVDPLNPSEICVATVVKVVGGRLLLHFDGWDPSRYDFWCDVDSPDIHPVGWCE 61

mbt repeat; The function of this repeat is unknown, but is found in a number of nuclear proteins such as drosophila sex comb on midleg protein. The repeat is found in up to four copies as in Swiss:Q9UHJ3. The repeat contains a completely conserved glutamate at its amino terminus that may be important for function.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  52 MKLETVNMCEPFYISPASVTKVFNnHFFQVTIDDLRPEPSklsMLCHADSLGILPVQWCLKNGVSLTPPK 121
Cdd:pfam02820   1 MKLEAVDPLNPSLICVATVVKVLG-GRLRLRFDGWDDSYD---FWCHADSPDIHPVGWCEKNGHPLQPPK 66

fourth malignant brain tumor (MBT) repeat found in the Drosophila melanogaster Polycomb protein Sfmbt (dSfmbt)-like family; The dSfmbt-like family includes Drosophila melanogaster Scm-like with four MBT domain-containing protein 1 (dSfmbt), as well as its two vertebrate homologs, MBT domain-containing protein 1 (MBTD1) and Lethal(3)malignant brain tumor-like protein 2 (L3MBTL2). dSfmbt is a Polycomb group (PcG) repressor involved in epigenetic regulation of gene expression. MBTD1 and L3MBTL2, also called L(3)mbt-like protein 2, are putative PcG proteins that specifically bind to monomethylated and dimethylated 'Lys-20' on histone H4. L3MBTL2 also binds histone H3 peptides which are monomethylated or dimethylated on 'Lys-4', 'Lys-9' or 'Lys-27'. Members of this family contain four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the fourth MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2462520368 154 RGFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVPEvIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20100     1 HGFKVGMKLEAVDLMEPRLICVATVTRVVGRLLRVHFDGWDDEFDQ-WVDCDSPDIYPVGWCELVGYPLQPP 71

SAM domain of Ph (polyhomeotic) proteins of Polycomb group; SAM (sterile alpha motif) domain of Ph (polyhomeotic) proteins of Polycomb group is a protein-protein interaction domain. Ph1,2,3 proteins are members of PRC1 complex. This complex is involved in transcriptional repression of Hox (Homeobox) cluster genes. It is recruited through methylated H3Lys27 and supports the repression state by mediating monoubiquitination of histone H2A. Proteins of the Ph1,2,3 subfamily contribute to anterior-posterior neural tissue specification during embryogenesis. Additionally, the P2 protein of zebrafish is known to be involved in epiboly and tailbud formation. SAM domains of Ph proteins may interact with each other, forming homooligomers, as well as with SAM domains of other proteins, in particular with the SAM domain of Scm (sex comb on midleg) proteins, forming heterooligomers. Homooligomers are similar to the ones formed by SAM Pointed domains of the TEL proteins. Such SAM/SAM oligomers apparently play a role in transcriptional repression through polymerization along the chromosome.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2462520368 567 SNPLEWTVTDVVRFIK-LTDCAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIERVK 633
Cdd:cd09577     1 SNPSKWSVEDVYEFIRsLPGCSDYAEEFRAQEIDGQALLLLKEDHLMSAMNIKLGPALKICAKINSLK 68

malignant brain tumor (MBT) repeat; The MBT repeat is a protein module that recognizes methylated lysine residues on histones and are thought to affect a variety of chromatin processes, including transcription. It exists as tandem repeats and is found in a number of nuclear proteins such as Drosophila sex comb on midleg protein. In the human genome, there are at least 9 MBT repeat proteins, each containing two, three or four MBT repeats. MBT repeat proteins use a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine (monomethyllysine and/or dimethyllysine).

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2462520368  48 FTVGMKLETVNMCEPFYISPASVTKVFnNHFFQVTIDDLrpEPSKLSMLCHADSLGILPVQWC 110
Cdd:cd20088     1 FKVGMKLEAVDPLNPSEICVATVVKVV-GGRLLLHFDGW--DPSRYDFWCDVDSPDIHPVGWC 60

first malignant brain tumor (MBT) repeat found in the Lethal(3)malignant brain tumor-like protein 1 (L3MBTL1)-like family; The L3MBTL1-like family includes L3MBTL1, L3MBTL3, and L3MBTL4. L3MBTL1, also called L(3)mbt-like, or L(3)mbt protein homolog, is a Polycomb group (PcG) protein that functions as a 'reader' of a network of post-translational modifications by specifically recognizing and binding mono- and dimethyllysine residues on target proteins. It acts as a chromatin compaction factor by binding mono- and dimethylated histone H1b/HIST1H1E at 'Lys-26' (H1bK26me1 and H1bK26me2) and histone H4 at 'Lys-20' (H4K20me1 and H4K20me2), leading to condensed chromatin and repressed transcription. L3MBTL3, also called L(3)mbt-like protein 3, or MBT-1, is a PcG protein that recognizes mono- and dimethylated lysine residues on histone tails. It also acts as a methyl-binding protein that binds the K142-methylated DNMT1 and recruits a novel CRL4(DCAF5) ubiquitin ligase to degrade DNMT1. L3MBTL4, also called L(3)mbt-like protein 4, or L3mbt-like 4, is a PcG protein that may act as a tumor suppressor. Members of this family contain three MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the first MBT repeat that contains the semi-aromatic cage and may bind methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2462520368 155 GFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTpVPEVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20101     5 GFKVGMKLEGIDPKHPSLFCVLSVAEVRGYRLRLHFDGYSE-CYDFWVNADSPDIFPVGWCEKTGHKLQPP 74

first malignant brain tumor (MBT) repeat found in Polycomb protein sex comb on midleg homolog 1; Sex comb on midleg homolog 1 (SCMH1) is a homolog of Drosophila Sex comb on midleg (Scm). It is a component of PRC1 (Polycomb repressive complex 1), which acts as an E3 ubiquitin ligase, both for histone H2A to silence transcription and for geminin to regulate its stability. SCMH1 provides the complex with an interaction domain for geminin. It contains two MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the first MBT repeat that does not contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368 128 FDWADYHKQHGAQEAPPFCFRN--TSFSRGFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPvPEVIVDVE 205
Cdd:cd20105     2 FSWDKYLKETGAVPAPVHCFKQsyTPPVNEFKIGMKLEAQDPRNTTSTCIATVVGLTGARLRLRLDGSDNK-NDFWRLVD 80

                          90       100
                  ....*....|....*....|
gi 2462520368 206 SMDIFPVGWCEANSYPLTAP 225
Cdd:cd20105    81 SSEIQPIGNCEKNGGMLQPP 100

third malignant brain tumor (MBT) repeat found in MBT domain-containing protein 1 (MBTD1); MBTD1 is a putative Polycomb group (PcG) protein that specifically binds to monomethylated and dimethylated 'Lys-20' on histone H4. MBTD1 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not seem to contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368  48 FTVGMKLETVNMCEPFYISPASVTKVFNNHFFQVTIDDLRPEPSKLSMLCHADSLGILPVQWCLKNGVSLTPPKGYSGQd 127
Cdd:cd20126     1 FKEGMKLEAIDPLNLSTICVATVRKVLANGYLMIGIDGSEAADGSDWFCYHATSPSIFPVGFCEINMIELTPPRGYKKP- 79

                          90
                  ....*....|.
gi 2462520368 128 FDWADYHKQHG 138
Cdd:cd20126    80 FKWFDYLRETG 90

fourth malignant brain tumor (MBT) repeat found in MBT domain-containing protein 1 (MBTD1); MBTD1 is a putative Polycomb group (PcG) protein that specifically binds to monomethylated and dimethylated 'Lys-20' on histone H4. MBTD1 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the fourth MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2462520368 155 GFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVPEvIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20129     2 GFRVGMKLEAVDLMEPRLVCVATVTRIIHRLLRIHFDGWEDEYDQ-WVDCESPDLYPVGWCQLTGYQLQPP 71

third malignant brain tumor (MBT) repeat found in Lethal(3)malignant brain tumor-like protein 3 (L3MBTL3); L3MBTL3, also called L(3)mbt-like protein 3, or MBT-1, is a Polycomb group (PcG) protein that recognizes mono- and dimethylated lysine residues on histone tails. It also acts as a methyl-binding protein that binds the K142-methylated DNMT1 and recruits a novel CRL4(DCAF5) ubiquitin ligase to degrade DNMT1. L3MBTL3 contains three MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that contains the semi-aromatic cage that may bind methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2462520368 153 SRGFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLqTPVPEVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20138     6 PHGFQKNMKLEVVDKRNPMLIRVATVADTDDHRVKVHFDGW-NNCYDYWIDADSPDIHPAGWCAKTGHPLQPP 77

SAM domain of Samd7,11 subfamily of Polycomb group; SAM (sterile alpha motif) domain is a protein-protein interaction domain. Phylogenetic analysis suggests that proteins of this subfamily are most closely related to SAM-Ph1,2,3 subfamily of Polycomb group. They are predicted transcriptional repressors in photoreceptor cells and pinealocytes of vertebrates. SAM domain containing protein 11 is also known as Mr-s (major retinal SAM) protein. In mouse, it is predominantly expressed in developing retinal photoreceptors and in adult pineal gland. The SAM domain is involved in homooligomerization of whole proteins (it was shown based on immunoprecipitation assay and mutagenesis), however its repression activity is not due to SAM/SAM interactions but to the C-terminal region.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2462520368 570 LEWTVTDVVRFI-KLTDCAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIER 631
Cdd:cd09579     2 RKWTVDDVCSFIgSLPGCAEYAQVFREHSIDGETLPLLTEEHLLNTMGLKLGPALKIRSQVAK 64

second malignant brain tumor (MBT) repeat found in the Polycomb protein sex comb on midleg family; The Sex comb on midleg (Scm) family of Polycomb proteins includes Drosophila melanogaster Scm protein, as well as two vertebrate homologs of Scm, Polycomb protein sex comb on midleg homolog 1 (SCMH1) and sex comb on midleg-like protein 2 (SCML2). Scm is a putative zinc finger protein that functions as a transcriptional regulator which represses multiple homeotic genes during embryonic stages. It coordinates Polycomb group (PcG) complexes, PRC1 (PcG-repressive complex 1) or PRC2 (PcG-repressive complex 2), and polymerizes to produce broad domains of PcG silencing. Both SCMH1 and SCML2 are components of PRC1, which acts as an E3 ubiquitin ligase both for histone H2A to silence transcription and for geminin to regulate its stability. SCMH1 provides the complex with an interaction domain for geminin. SCML2 is a germline-specific Polycomb protein that acts as a critical regulator of heterochromatin organization in spermatogenesis. Members of this family contain two MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the second MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462520368 156 FTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVpEVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20092     6 FKVGMKLEAVDRKNPQLICPATVGDVDGDEIHISFDGWRGAF-DYWCRYDSRDIFPVGWCKKTGHPLQPP 74

fourth malignant brain tumor (MBT) repeat found in Lethal(3)malignant brain tumor-like protein 2 (L3MBTL2); L3MBTL2, also called L(3)mbt-like protein 2, is a putative Polycomb group (PcG) protein that binds to monomethylated and dimethylated 'Lys-20' on histone H4 and also binds histone H3 peptides which are monomethylated or dimethylated on 'Lys-4', 'Lys-9' or 'Lys-27'. L3MBTL2 orchestrates ubiquitin signalling by dictating the sequential recruitment of RNF8 and RNF168 after DNA damage. It is an integral component of the polycomb repressive complex 1.6 (PRC1.6) and has been implicated in transcriptional repression and chromatin compaction. L3MBTL2 contains four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the fourth MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2462520368 153 SRGFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVPEvIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20130     3 NHGFKVGMKLEAVDLMEPRLICVATVKRVVHRLLSIHFDGWDSEYDQ-WVDCESPDIYPVGWCELTGYQLQPP 74

SAM domain of Scm-like-4MBT proteins of Polycomb group; SAM (sterile alpha motif) domain of Scm-like-4MBT (Sex comb on midleg like, Malignant Brain Tumor) subfamily proteins of the polycomb group is a putative protein-protein interaction domain. Additionally to the SAM domain, most of the proteins of this subfamily have 4 MBT repeats. In Drosophila SAM-Scm-like-4MBT protein (known as dSfmbt) is a member of Pho repressive complex (PhoRC). Additionally to dSfmbt, the PhoRC complex includes Pho or Pho-like proteins. This complex is responsible for HOX (Homeobox) gene silencing: Pho or Pho-like proteins bind DNA and dSmbt binds methylated histones. dSmbt can interact with mono- and di-methylated histones H3 and H4 (however this activity has been shown for the MBT repeats, while exact function of the SAM domain is unclear). Besides interaction with histones, dSmbt can interact with Scm (a member of PRC complex), but this interaction also seems to be SAM domain independent.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2462520368 569 PLEWTVTDVVRFIKLTDCAPLAKIFQEQDIDGQALLLLTLPTVQECMELKLGPAIKLCHQIERVK 633
Cdd:cd09580     1 PSTWGVKDVSQFLRENDCGAYCECFCRQNIDGKRLLSLTKEQIMTLTGMKVGPSLKIYDLIQQLK 65

fourth malignant brain tumor (MBT) repeat found in Lethal(3)malignant brain tumor-like protein 4 (L3MBTL4); L3MBTL4, also called L(3)mbt-like protein 4, or L3mbt-like 4, is a Polycomb group (PcG) protein that may act as a tumor suppressor. L3MBTL4 contains three MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that contains the semi-aromatic cage that may bind methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2462520368 155 GFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVpEVIVDVESMDIFPVGWCEANSYPLTAPHKTV 229
Cdd:cd20139     8 GFQVNMKLEAVDKRNPILIRVATIVDKDDHRIKLHFDGWDHNY-DFWVDADSPDIHPVGWCDKTGHALQVPLGAS 81

second malignant brain tumor (MBT) repeat found in Drosophila melanogaster Polycomb protein sex comb on midleg (Scm) and similar proteins; Scm is a putative zinc finger protein that functions as a transcriptional regulator which represses multiple homeotic genes during embryonic stages. It coordinates Polycomb group (PcG) complexes, PRC1 (PcG-repressive complex 1) or PRC2 (PcG-repressive complex 2), and polymerizes to produce broad domains of PcG silencing. Scm contains two MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the second MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2462520368  44 RSHFFTVGMKLETVNMCEPFYISPASVTKVFNNHFFqVTIDDLRpepSKLSMLCHADSLGILPVQWCLKNGVSLTPP 120
Cdd:cd20110     2 ESNLFKVGMKLEAVDRKNPHLICPATVGAVKDDQIF-VTFDGWR---GAFDYWCRYDSRDIFPVGWCARSGHPLQPP 74

first malignant brain tumor (MBT) repeat found in the Scm-like with four MBT domains protein (SFMBT) family; The SFMBT family includes SFMBT1 and SFMBT2. SFMBT1, also called renal ubiquitous protein 1, is a transcriptional repressor protein that selectively binds the N-terminal tail of histone H3 and functions as a chromatin reader in regulating epigenetic silencing and the myogenic gene program. It mediates the recruitment of corepressor complexes to target genes, followed by chromatin compaction and repression of transcription. SFMBT2, also called Scm-like with 4 MBT domains protein 2, is a transcriptional repressor of the HOXB13 gene. It is required for trophoblast maintenance and placenta development. It also negatively regulates cell migration and invasion in prostate cancer cells. Members of this family contain four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the first MBT repeat that contains a partially conserved semi-aromatic cage.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2462520368 155 GFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVP-EVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20093     3 GFKPGMKLEVPNKNNPDTYWVATVVMTCGPLLRLRYVGYEDDRSaDFWCDLSSGDVHPIGWCAQNGKPLQPP 74

first malignant brain tumor (MBT) repeat found in Lethal(3)malignant brain tumor-like protein 3 (L3MBTL3); L3MBTL3, also called L(3)mbt-like protein 3, or MBT-1, is a Polycomb group (PcG) protein that recognizes mono- and dimethylated lysine residues on histone tails. It also acts as a methyl-binding protein that binds the K142-methylated DNMT1 and recruits a novel CRL4(DCAF5) ubiquitin ligase to degrade DNMT1. L3MBTL3 contains three MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the first MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2462520368 155 GFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLqTPVPEVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20132     5 GFKVGMKLEGVDPEHQSMYCVLTVAEVCGYRIRLHFDGY-SDCYDFWVNADSPDIHPVGWCEKTGHKLHPP 74

fourth malignant brain tumor (MBT) repeat found in the Drosophila melanogaster Polycomb protein Sfmbt (dSfmbt)-like family; The dSfmbt-like family includes Drosophila melanogaster Scm-like with four MBT domain-containing protein 1 (dSfmbt), as well as its two vertebrate homologs, MBT domain-containing protein 1 (MBTD1) and Lethal(3)malignant brain tumor-like protein 2 (L3MBTL2). dSfmbt is a Polycomb group (PcG) repressor involved in epigenetic regulation of gene expression. MBTD1 and L3MBTL2, also called L(3)mbt-like protein 2, are putative PcG proteins that specifically bind to monomethylated and dimethylated 'Lys-20' on histone H4. L3MBTL2 also binds histone H3 peptides which are monomethylated or dimethylated on 'Lys-4', 'Lys-9' or 'Lys-27'. Members of this family contain four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the fourth MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2462520368  46 HFFTVGMKLETVNMCEPFYISPASVTKV----FNNHFfqvtiDDLRPEpskLSMLCHADSLGILPVQWCLKNGVSLTPP 120
Cdd:cd20100     1 HGFKVGMKLEAVDLMEPRLICVATVTRVvgrlLRVHF-----DGWDDE---FDQWVDCDSPDIYPVGWCELVGYPLQPP 71

third malignant brain tumor (MBT) repeat found in the Drosophila melanogaster Polycomb protein Sfmbt (dSfmbt)-like family; The dSfmbt-like family includes Drosophila melanogaster Scm-like with four MBT domain-containing protein 1 (dSfmbt), as well as its two vertebrate homologs, MBT domain-containing protein 1 (MBTD1) and Lethal(3)malignant brain tumor-like protein 2 (L3MBTL2). dSfmbt is a Polycomb group (PcG) repressor involved in epigenetic regulation of gene expression. MBTD1 and L3MBTL2, also called L(3)mbt-like protein 2, are putative PcG proteins that specifically bind to monomethylated and dimethylated 'Lys-20' on histone H4. L3MBTL2 also binds histone H3 peptides which are monomethylated or dimethylated on 'Lys-4', 'Lys-9' or 'Lys-27'. Members of this family contain four MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the third MBT repeat that does not seem to contain a semi-aromatic cage and may not bind methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2462520368 156 FTKNMKLEAVNPRNPGELCVASVVSV--KGRLMwLHLEGLQTPVPEV--IVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20099     1 FKVGMKLEAVDPLNLSSICVATVRKVlrFGYLV-IGIDGPSADDGSDwfCCHASSPFIFPVGFAEKNGIELTPP 73

second malignant brain tumor (MBT) repeat found in Drosophila melanogaster Polycomb protein sex comb on midleg (Scm) and similar proteins; Scm is a putative zinc finger protein that functions as a transcriptional regulator which represses multiple homeotic genes during embryonic stages. It coordinates Polycomb group (PcG) complexes, PRC1 (PcG-repressive complex 1) or PRC2 (PcG-repressive complex 2), and polymerizes to produce broad domains of PcG silencing. Scm contains two MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the second MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2462520368 153 SRGFTKNMKLEAVNPRNPGELCVASVVSVKGRLMWLHLEGLQTPVpEVIVDVESMDIFPVGWCEANSYPLTAP 225
Cdd:cd20110     3 SNLFKVGMKLEAVDRKNPHLICPATVGAVKDDQIFVTFDGWRGAF-DYWCRYDSRDIFPVGWCARSGHPLQPP 74

second malignant brain tumor (MBT) repeat found in sex comb on midleg-like protein 2 (SCML2) and similar proteins; SCML2 is a homolog of Drosophila Sex comb on midleg (Scm). It is a component of PRC1 (Polycomb repressive complex 1), which acts as an E3 ubiquitin ligase, both for histone H2A to silence transcription and for geminin to regulate its stability. SCML2 is a germline-specific Polycomb protein that acts as a critical regulator of heterochromatin organization in spermatogenesis. SCML2 contains two MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the second MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2462520368  46 HFFTVGMKLETVNMCEPFYISPASVTKVFNNHFFqVTIDDLRpepSKLSMLCHADSLGILPVQWCLKNGVSLTPP 120
Cdd:cd20109     4 NNFKVGMKLEAIDKKNPYLICPATIGDVKGDEVF-ITFDGWR---GAFDYWCKYDSRDIFPVGWCRLTGDVLQPP 74

second malignant brain tumor (MBT) repeat found in the Polycomb protein sex comb on midleg family; The Sex comb on midleg (Scm) family of Polycomb proteins includes Drosophila melanogaster Scm protein, as well as two vertebrate homologs of Scm, Polycomb protein sex comb on midleg homolog 1 (SCMH1) and sex comb on midleg-like protein 2 (SCML2). Scm is a putative zinc finger protein that functions as a transcriptional regulator which represses multiple homeotic genes during embryonic stages. It coordinates Polycomb group (PcG) complexes, PRC1 (PcG-repressive complex 1) or PRC2 (PcG-repressive complex 2), and polymerizes to produce broad domains of PcG silencing. Both SCMH1 and SCML2 are components of PRC1, which acts as an E3 ubiquitin ligase both for histone H2A to silence transcription and for geminin to regulate its stability. SCMH1 provides the complex with an interaction domain for geminin. SCML2 is a germline-specific Polycomb protein that acts as a critical regulator of heterochromatin organization in spermatogenesis. Members of this family contain two MBT (malignant brain tumor) repeats. The MBT repeat is a protein module that recognizes methylated lysine residues on histones. MBT repeats contain a semi-aromatic cage to accommodate methyllysine and show specificity towards the lower methylation states of lysine. This model corresponds to the second MBT repeat that contains the semi-aromatic cage that binds methylated lysine residues.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2462520368  47 FFTVGMKLETVNMCEPFYISPASVTKVFNNHFFqVTIDDLRpepSKLSMLCHADSLGILPVQWCLKNGVSLTPPK 121
Cdd:cd20092     5 MFKVGMKLEAVDRKNPQLICPATVGDVDGDEIH-ISFDGWR---GAFDYWCRYDSRDIFPVGWCKKTGHPLQPPG 75