basic helix-loop-helix (bHLH) domain found in oligodendrocyte transcription factor 3 (Oligo3) and similar proteins; Oligo3, also termed Class B basic helix-loop-helix protein 7 (bHLHb7), or Class E basic helix-loop-helix protein 20 (bHLHe20), is a bHLH transcription factor that is expressed in the ventricular zone of the dorsal alar plate of the hindbrain and involved in regulating the development of dorsal and ventral spinal cord. It may determine the distinct specification program of class A neurons in the dorsal part of the spinal cord and suppress specification of class B neurons.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 28411948  69 KYKIKKQLSEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 148
Cdd:cd18941   1 KYKIKKQLSEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 80

                .
gi 28411948 149 G 149
Cdd:cd18941  81 G 81

basic helix-loop-helix (bHLH) domain found in oligodendrocyte transcription factor 3 (Oligo3) and similar proteins; Oligo3, also termed Class B basic helix-loop-helix protein 7 (bHLHb7), or Class E basic helix-loop-helix protein 20 (bHLHe20), is a bHLH transcription factor that is expressed in the ventricular zone of the dorsal alar plate of the hindbrain and involved in regulating the development of dorsal and ventral spinal cord. It may determine the distinct specification program of class A neurons in the dorsal part of the spinal cord and suppress specification of class B neurons.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 28411948  69 KYKIKKQLSEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 148
Cdd:cd18941   1 KYKIKKQLSEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 80

                .
gi 28411948 149 G 149
Cdd:cd18941  81 G 81

helix loop helix domain;

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*
gi 28411948     89 NGRERKRMHDLNLAMDGLREVMPYahGPSVRKLSKIATLLLARNYILMLTSSLEE 143
Cdd:smart00353   1 NARERRRRRKINEAFDELRSLLPT--LPKNKKLSKAEILRLAIEYIKSLQEELQK 53

basic helix-loop-helix (bHLH) domain found in oligodendrocyte transcription factor 3 (Oligo3) and similar proteins; Oligo3, also termed Class B basic helix-loop-helix protein 7 (bHLHb7), or Class E basic helix-loop-helix protein 20 (bHLHe20), is a bHLH transcription factor that is expressed in the ventricular zone of the dorsal alar plate of the hindbrain and involved in regulating the development of dorsal and ventral spinal cord. It may determine the distinct specification program of class A neurons in the dorsal part of the spinal cord and suppress specification of class B neurons.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 28411948  69 KYKIKKQLSEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 148
Cdd:cd18941   1 KYKIKKQLSEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 80

                .
gi 28411948 149 G 149
Cdd:cd18941  81 G 81

basic helix-loop-helix (bHLH) domain found in oligodendrocyte transcription factors, Oligo2, Oligo3 and similar proteins; The family includes two bHLH transcription factors, Oligo2 and Oligo3. Oligo2, also termed Class B basic helix-loop-helix protein 1 (bHLHb1), or Class E basic helix-loop-helix protein 19 (bHLHe19), or protein kinase C-binding protein 2, or protein kinase C-binding protein RACK17, is required for oligodendrocyte and motor neuron specification in the spinal cord, as well as for the development of somatic motor neurons in the hindbrain. It cooperates with OLIG1 to establish the MN progenitors (pMN) domain of the embryonic neural tube. Oligo3, also termed Class B basic helix-loop-helix protein 7 (bHLHb7), or Class E basic helix-loop-helix protein 20 (bHLHe20), is expressed in the ventricular zone of the dorsal alar plate of the hindbrain and involved in regulating the development of dorsal and ventral spinal cord. It may determine the distinct specification program of class A neurons in the dorsal part of the spinal cord and suppress specification of class B neurons.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 28411948  84 LRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKR 146
Cdd:cd19725   1 LRLKINSRERKRMHDLNSALDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTNSLEEMKR 63

basic helix-loop-helix (bHLH) domain found in Class E basic helix-loop-helix protein 22 (bHLHe22) and similar proteins; bHLHe22, also termed Class B basic helix-loop-helix protein 5 (bHLHb5), or trinucleotide repeat-containing gene 20 protein, is an OLIG-related bHLH neural-specific transcriptional repressor that is expressed in both excitatory (unipolar brush cells) and inhibitory neurons (cartwheel cells) of the dorsal cochlear nucleus (DCN) during development. It is important for the proper development and/or survival of a number of neural cell types.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 28411948  84 LRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLEEMKRLV 148
Cdd:cd18954   1 VRLNINARERRRMHDLNDALDELRAVIPYAHSPSVRKLSKIATLLLAKNYILMQANALEEMRRLV 65

basic helix-loop-helix (bHLH) domain found in oligodendrocyte transcription factor 1 (Oligo1) and similar proteins; Oligo1, also termed Class B basic helix-loop-helix protein 6 (bHLHb6), or Class E basic helix-loop-helix protein 21 (bHLHe21), is a bHLH transcription factor that promotes formation and maturation of oligodendrocytes, especially within the brain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 28411948  82 QQLRLKINGRERKRMHDLNLAMDGLREVM-PYAHGPSV----RKLSKIATLLLARNYILMLTSSLEEMKRLV 148
Cdd:cd18942   4 QQLRRKINSRERKRMQDLNLAMDALREVIlPYSAAHCQsspgRKLSKIATLLLARNYILLLGSSLQELRRLL 75

tissue specific basic helix-loop-helix (bHLH-TS) domain family; Tissue specific bHLH domain family includes transcription regulators whose expression are restricted to certain tissues. They are involved in cell-fate determination and process in neurogenesis, cardiogenesis, myogenesis, and hematopoiesis and include proteins from myogenic regulatory factor (MRF) family, twist-related protein (TWIST) family, scleraxis-like family, heart- and neural crest derivatives-expressed protein (HAND) family, helix-loop-helix protein (HEN) family, musculin-like family, germline alpha (FIGLA) family, T-cell acute lymphocytic leukemia protein/ lymphoblastic leukemia-derived sequence (TAL/LYL) family, ovary, uterus and testis protein (OUT) family, mesoderm posterior protein (Mesp) family, muscle, intestine and stomach expression 1 (MIST-1) family, protein atonal homologs (ATOH) family, neurogenin (NGN) family, neurogenic differentiation factor (NeuroD) family, achaete-scute complex-like (ASCL) family, Fer3-like protein (FERD3L)-like family, and Oligodendrocyte lineage genes (OLIG) family of transcription factors.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd11390   1 RNAANARERRRMHDLNDAFEALRKVLPTV--PPDKKLSKIETLRLAINYIAALSDLL 55

basic helix-loop-helix (bHLH) domain found in neurogenic differentiation factor (NeuroD) family; The NeuroD family includes NeuroD1, NeuroD2, NeuroD4 and NeuroD6. NeuroD1, also termed Class A basic helix-loop-helix protein 3 (bHLHa3), is a neuronal bHLH transcription factor involved in the development and maintenance of the endocrine pancreas and neuronal elements. It acts as an essential regulator of glutamatergic neuronal differentiation. Loss of NeuroD1 causes ataxia, cerebellar hypoplasia, sensorineural deafness, and severe retinal dystrophy in mice. NeuroD2, also termed Class A basic helix-loop-helix protein 1 (bHLHa1), or NeuroD-related factor (NDRF), is a neuronal calcium-dependent bHLH transcription factor that induces neuronal differentiation and promotes neuronal survival. It plays a central role in thalamocortical synaptic maturation. NeuroD2 mediates calcium-dependent transcription activation by binding to E box-containing promoter. NeuroD4, also termed Class A basic helix-loop-helix protein 4 (bHLHa4), or protein atonal homolog 3 (ATH-3), or Atoh3, or Math-3, is a bHLH transcriptional activator that mediates neuronal differentiation. NeuroD6, also termed Class A basic helix-loop-helix protein 2 (bHLHa2), or protein atonal homolog 2 (ATH-2), or Atoh2, or Math2, or Nex1, is a neurogenic bHLH transcription factor involved in neuronal development, differentiation, and survival in Alzheimer's disease (AD) brains of both cohorts. It plays an integrative role in coordinating increase in mitochondrial mass with cytoskeletal remodeling, suggesting that it may act as a co-regulator of neuronal differentiation and energy metabolism.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMP-YAHgpsVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd11427   1 RVKANARERNRMHGLNDALDNLRKVVPcYSK---TQKLSKIETLRLARNYIWALSEIL 55

basic helix-loop-helix (bHLH) domain found in muscle, intestine and stomach expression 1 (MIST-1) and similar proteins; MIST-1, also termed Class A basic helix-loop-helix protein 15 (bHLHa15), or Class B basic helix-loop-helix protein 8 (bHLHb8), is a bHLH transcription factor expressed in pancreatic acinar cells and other serous exocrine cells. It is essential for cytoskeletal organization and secretory activity. It also functions as a potent endoplasmic reticulum (ER) stress-inducible transcriptional regulator. MIST-1 is capable of binding to E-box (CANNTG) motifs as a homodimer or a heterodimer with E-proteins (E12 and E47) to regulate transcription.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPyaHGPSVRKLSKIATLLLARNYILMLTSSLEEM 144
Cdd:cd19711   2 RLESNERERQRMHKLNNAFQALREVIP--HVRAEKKLSKIETLTLAKNYIKSLTTTILNM 59

basic helix-loop-helix (bHLH) domain found in neurogenin (NGN) family; The NGN family includes three neural-specific bHLH transcription factors, NGN1-3, which may function at neuroblast selection genes during the development of several neuronal lineages. NGN-1, also termed Class A basic helix-loop-helix protein 6 (bHLHa6), or neurogenic basic-helix-loop-helix protein, or neurogenic differentiation factor 3 (NeuroD3), is a neural-specific bHLH transcription factor involved in the initiation of neuronal differentiation. NGN-2, also termed Class A basic helix-loop-helix protein 8 (bHLHa8), or protein atonal homolog 4 (ATOH4), is a neural-specific bHLH transcription factor required for sensory neurogenesis. NGN-3, also termed Class A basic helix-loop-helix protein 7 (bHLHa7), or protein atonal homolog 5 (ATOH5), is a neural-specific bHLH transcription factor expressed in the developing central nervous system and the embryonic pancreas. It is involved in neurogenesis and plays an important role in spermatogenesis.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd11428   2 RLKANDRERNRMHNLNDALDALREVLPSF--PDETKLTKIETLRFAHNYIWALSETLK 57

basic helix-loop-helix (bHLH) domain found in neurogenin-3 (NGN-3) and similar proteins; NGN-3, also termed Class A basic helix-loop-helix protein 7 (bHLHa7), or protein atonal homolog 5 (ATOH5), is a neural-specific bHLH transcription factor expressed in the developing central nervous system and the embryonic pancreas. It is involved in neurogenesis and plays an important role in spermatogenesis.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd19718   9 RMKANDRERNRMHNLNSALDALRSVLPTF--PDDAKLTKIETLRFAHNYIWALTETL 63

basic helix-loop-helix (bHLH) domain found in neurogenic differentiation factor 2 (NeuroD2) and similar proteins; NeuroD2, also termed Class A basic helix-loop-helix protein 1 (bHLHa1), or NeuroD-related factor (NDRF), is a neuronal calcium-dependent bHLH transcription factor that induces neuronal differentiation and promotes neuronal survival. It plays a central role in thalamocortical synaptic maturation. NeuroD2 mediates calcium-dependent transcription activation by binding to E box-containing promoter.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 28411948  73 KKQLSEQDLQQLRL---KINGRERKRMHDLNLAMDGLREVMP-YAhgpSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd19720  21 KRKMTKARLERSKLrrqKANARERNRMHDLNSALDNLRKVVPcYS---KTQKLSKIETLRLAKNYIWALSEIL 90

Helix-loop-helix DNA-binding domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 28411948    85 RLKINGRERKRMHDLNLAMDGLREVMPyaHGPSVRKLSKIATLLLARNYILMLT 138
Cdd:pfam00010   2 REAHNERERRRRDRINDAFDELRELLP--TLPPDKKLSKAEILRLAIEYIKHLQ 53

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster protein taxi and similar proteins; Protein taxi, also termed protein delilah (Dei), is a bHLH transcription factor that is involved in regulation of cell adhesion and attachment that is expressed in specialized cells that provide anchoring sites to either muscles (tendon cells), or proprioceptors (chordotonal attachment cells) during embryonic development. It probably plays an important role in the differentiation of epidermal cells into the tendon cells that form the attachment sites for all muscles.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVR-KLSKIATLLLARNYILMLTSSL 141
Cdd:cd11431   2 RKTANARERDRMREINDAFEALRRAVPEYPVAGKDgKLTKITTLRLAMNYIKALTDLL 59

basic helix-loop-helix (bHLH) domain found in neurogenic differentiation factor 1 (NeuroD1) and similar proteins; NeuroD1, also termed Class A basic helix-loop-helix protein 3 (bHLHa3), is a neuronal bHLH transcription factor involved in the development and maintenance of the endocrine pancreas and neuronal elements. It acts as an essential regulator of glutamatergic neuronal differentiation. Loss of NeuroD1 causes ataxia, cerebellar hypoplasia, sensorineural deafness, and severe retinal dystrophy in mice.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 28411948  73 KKQLSEQDLQQL---RLKINGRERKRMHDLNLAMDGLREVMP-YAhgpSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd19719  14 KKKMTKARLERFkmrRMKANARERNRMHGLNAALDNLRKVVPcYS---KTQKLSKIETLRLAKNYIWALSEIL 83

basic helix-loop-helix (bHLH) domain found in Fer3-like protein (FERD3L), pancreas transcription factor 1 subunit alpha (PTF1A) and similar proteins; The family corresponds to a group of bHLH transcription factors, including FERD3L and PTF1A. FERD3L, also termed basic helix-loop-helix protein N-twist, or Class A basic helix-loop-helix protein 31 (bHLHa31), or nephew of atonal 3 (NATO3), or Neuronal twist (NTWIST), is expressed in the developing central nervous system (CNS). It regulates floor plate (FP) cells development. FP is a critical organizing center located at the ventral-most midline of the neural tube. FERD3L binds to the E-box and functions as inhibitor of transcription. PTF1A, also termed Class A basic helix-loop-helix protein 29 (bHLHa29), or pancreas-specific transcription factor 1a, or bHLH transcription factor p48, or p48 DNA-binding subunit of transcription factor PTF1 (PTF1-p48), is implicated in the cell fate determination in various organs. It binds to the E-box consensus sequence 5'-CANNTG-3' and plays a role in early and late pancreas development and differentiation.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 28411948  89 NGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd19686   6 NIRERKRMRSINDAFDGLRRHIPTF--PYEKRLSKVDTLRLAIQYINFLTELL 56

basic helix-loop-helix (bHLH) domain found in protein atonal homolog 7 (ATOH7) and similar proteins; ATOH7, also termed Class A basic helix-loop-helix protein 13 (bHLHa13), or helix-loop-helix protein hATH-5 (hATH5), or Math5, is a bHLH transcription factor involved in the differentiation of retinal ganglion cells.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPyaHGPSVRKLSKIATLLLARNYILMLTSSLEEMKR 146
Cdd:cd19714   9 RLAANARERRRMQGLNTAFDRLRKVVP--QWGQDKKLSKYETLQMALSYIMALTRILAEAER 68

basic helix-loop-helix (bHLH) domain found in protein atonal homolog 1 (ATOH1) and similar proteins; ATOH1, also termed Class A basic helix-loop-helix protein 14 (bHLHa14), or helix-loop-helix protein hATH-1 (hATH1), or Math1, or Cath1, is a proneural bHLH transcription factor that is essential for inner ear hair cell differentiation. It dimerizes with E47 and activates E-box (CANNTG) dependent transcription. ATOH1 is a mammalian homolog of the Drosophila melanogaster gene atonal and mouse atonal homolog 1 (Math1).

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 28411948  82 QQLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPsvRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd19713   4 KQRRLAANARERRRMHGLNHAFDQLRNVIPSFNND--KKLSKYETLQMAQIYINALSELLQ 62

basic helix-loop-helix (bHLH) domain found in mesoderm posterior protein (Mesp) family; Mesp, a bHLH tissue specific transcription factor, acts as a key regulator of the cardiovascular transcriptional network by inducing directly and/or indirectly the expression of the majority of key cardiovascular transcription factors. The Mesp family includes two bHLH transcription factors, Mesp1 and Mesp2. Mesp1, also termed Class C basic helix-loop-helix protein 5 (bHLHc5), promotes cardiovascular differentiation during embryonic development and embryonic stem cell differentiation. Mesp2, also termed Class C basic helix-loop-helix protein 6 (bHLHc6), plays an important role in somitogenesis. The family also includes mesogenin-1 (Msgn1) and similar proteins. Msgn1, also termed paraxial mesoderm-specific mesogenin1, or pMesogenin1 (pMsgn1), is a bHLH transcription factor required for maturation and segmentation of paraxial mesoderm. It may regulate the expression of T-box transcription factors essential for mesoderm formation and differentiation.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd11425   2 RQLANERERLRMRTLADALGELRQHLPPSVAPKGKRLSKIQTLKYAIRYIGYLGNVLQ 59

basic helix-loop-helix (bHLH) domain found in pancreas transcription factor 1 subunit alpha (PTF1A) and similar proteins; PTF1A, also termed Class A basic helix-loop-helix protein 29 (bHLHa29), or pancreas-specific transcription factor 1a, or bHLH transcription factor p48, or p48 DNA-binding subunit of transcription factor PTF1 (PTF1-p48), is a bHLH transcription factor implicated in the cell fate determination in various organs. It binds to the E-box consensus sequence 5'-CANNTG-3' and plays a role in early and late pancreas development and differentiation.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLT 138
Cdd:cd11417   2 RQAANLRERRRMQSINDAFEGLRSHIPTL--PYEKRLSKVDTLRLAIGYINFLS 53

basic helix-loop-helix (bHLH) domain found in heart- and neural crest derivatives-expressed protein (HAND) family; The HAND family includes two bHLH transcription factors, HAND1 and HAND2. HAND1, also termed Class A basic helix-loop-helix protein 27 (bHLHa27), or extraembryonic tissues, heart, autonomic nervous system and neural crest derivatives-expressed protein 1 (eHAND), plays an essential role in both trophoblast-giant cells differentiation and in cardiac morphogenesis. HAND2, also termed Class A basic helix-loop-helix protein 26 (bHLHa26), or deciduum, heart, autonomic nervous system and neural crest derivatives-expressed protein 2 (dHAND), is essential for cardiac morphogenesis, particularly for the formation of the right ventricle and of the aortic arch arteries.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPyaHGPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd11466   2 RGSANKKERRRTQSINSAFADLRECIP--NVPADTKLSKIKTLRLATSYIAYLMDVL 56

basic helix-loop-helix (bHLH) domain found in heart- and neural crest derivatives-expressed protein 2 (HAND2) and similar proteins; HAND2, also termed Class A basic helix-loop-helix protein 26 (bHLHa26), or deciduum, heart, autonomic nervous system and neural crest derivatives-expressed protein 2 (dHAND), is a bHLH transcription factor that is essential for cardiac morphogenesis, particularly for the formation of the right ventricle and of the aortic arch arteries.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSLEE 143
Cdd:cd11471   2 RGTANRKERRRTQSINSAFAELRECIPNV--PADTKLSKIKTLRLATSYIAYLMDLLAK 58

basic helix-loop-helix (bHLH) domain found in transcription factor 15 (TCF-15) and similar proteins; TCF-15, also termed Class A basic helix-loop-helix protein 40 (bHLHa40), or paraxis, or protein bHLH-EC2, is a bHLH transcription factor expressed in caudal lateral and paraxial mesoderm dermomyotome and sclerotome fore limb buds during embryo development. It may function as an early transcriptional regulator involved in the patterning of the mesoderm and in lineage determination of cell types derived from the mesoderm.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd11470   9 RQAANARERDRTQSVNTAFTALRTLIPTE--PVDRKLSKIETLRLASSYIAHLANVL 63

basic helix-loop-helix (bHLH) domain found in twist-related protein (TWIST) family; The TWIST family includes TWIST1 and TWIST2, which are highly homologous bHLH transcription factors that promote epithelial-mesenchymal transition (EMT) during development and tumor metastasis. They are involved in the negative regulation of cellular determination and in the differentiation of several lineages, including myogenesis, osteogenesis, and neurogenesis. TWIST factors express in broad partially-overlapping patterns during embryo development and dimerize with a broad sets of dimer partners that form numerous unique transcriptional complexes to regulate embryonic development.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
gi 28411948  85 RLKINGRERKRMHDLNLAMDGLREVMPYAhgPSvRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd11464   2 RVLANVRERQRTQSLNEAFTSLRKIIPTL--PS-DKLSKIQTLKLAARYIDFLYQVLR 56

basic helix-loop-helix (bHLH) domain found in twist-related protein 2 (TWIST2) and similar proteins; TWIST2, also termed Class A basic helix-loop-helix protein 39 (bHLHa39), or Dermis-expressed protein 1, or Dermo-1, is a bHLH transcription factor that regulates the development of mesenchymal tissues and plays a critical role in embryogenesis. It binds to the E-box consensus sequence 5'-CANNTG-3' as a heterodimer and inhibits transcriptional activation by MYOD1, MYOG, MEF2A and MEF2C.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 28411948  77 SEQDLQQLRLKINGRERKRMHDLNLAMDGLREVMPYAhgPSvRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd19700  10 SYEELQSQRILANVRERQRTQSLNEAFAALRKIIPTL--PS-DKLSKIQTLKLAARYIDFLYQVLQ 72

basic helix-loop-helix (bHLH) domain found in heart- and neural crest derivatives-expressed protein 1 (HAND1) and similar proteins; HAND1, also termed Class A basic helix-loop-helix protein 27 (bHLHa27), or extraembryonic tissues, heart, autonomic nervous system and neural crest derivatives-expressed protein 1 (eHAND), is a bHLH transcription factor that plays an essential role in both trophoblast-giant cells differentiation and in cardiac morphogenesis.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 28411948  91 RERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd18952   9 KERRRTESINSAFAELRECIPNV--PADTKLSKIKTLRLATSYIAYLMDVL 57

basic helix-loop-helix (bHLH) domain found in T-cell acute lymphocytic leukemia protein 2 (TAL-2) and similar proteins; TAL-2, also termed Class A basic helix-loop-helix protein 19 (bHLHa19), is a bHLH transcription factor essential for the normal brain development. It has been implicated in T-cell acute lymphoblastic leukemia.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 28411948  89 NGRERKRMHDLNLAMDGLREVMPyAHGPSvRKLSKIATLLLARNYILMLTSSLEE 143
Cdd:cd19707   7 NTRERWRQQNVNSAFAELRKLIP-THPPD-KKLSKNEILRLAMKYINFLVKLLGD 59

basic helix-loop-helix (bHLH) domain found in musculin and similar proteins; Musculin, also termed activated B-cell factor 1 (ABF-1), or Class A basic helix-loop-helix protein 22 (bHLHa22), is a bHLH transcription factor expressed in activated B lymphocytes. It acts as a transcription repressor capable of inhibiting the transactivation capability of TCF3/E47. Musculin may play a role in regulating antigen-dependent B-cell differentiation. The mouse homolog, musculin, is suggested to be a repressor of myogenesis that is expressed in developing muscle and in the spleen. Musculin heterodimerizes with products of the E2A gene.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 28411948  82 QQLRLKINGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSLEE 143
Cdd:cd19703   2 QSQRNAANARERARMRVLSKAFSRLKTSLPWV--PPDTKLSKLDTLRLASSYIAHLRQLLQE 61

basic helix-loop-helix (bHLH) domain found in achaete-scute-like protein 1 (ASCL-1) and similar proteins; ASCL-1, also termed Class A basic helix-loop-helix protein 46 (bHLHa46), or achaete-scute homolog 1 (ASH-1), or mammalian achaete scute homolog 1 (Mash1), is a neural-specific bHLH transcription factor that is expressed in subsets of neural progenitors in both the central and peripheral nervous system. It plays a key role in neuronal differentiation and specification in the nervous system.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 28411948  89 NGRERKRMHDLNLAMDGLREVMPyaHGPSVRKLSKIATLLLARNYILMLTSSLEE 143
Cdd:cd19742  10 NERERNRVKLVNMGFATLREHVP--NGAANKKMSKVETLRSAVEYIRALQQLLDE 62

basic helix-loop-helix (bHLH) domain found in the mesoderm posterior protein (Mesp) family; Mesp, a bHLH tissue specific transcription factor, acts as a key regulator of the cardiovascular transcriptional network by inducing directly and/or indirectly the expression of the majority of key cardiovascular transcription factors. The Mesp family includes two bHLH transcription factors, Mesp1 and Mesp2. Mesp1, also termed Class C basic helix-loop-helix protein 5 (bHLHc5), promotes cardiovascular differentiation during embryonic development and embryonic stem cell differentiation. Mesp2, also termed Class C basic helix-loop-helix protein 6 (bHLHc6), plays an important role in somitogenesis.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 28411948  91 RERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd18938   8 REKLRMRDLAKALHNLRRYLPPSVAPAGQSLTKIETLRLTIRYISHLSAQL 58

basic helix-loop-helix (bHLH) domain found in ovary, uterus and testis protein (OUT) family; The OUT family includes transcription factor 23 (TCF-23), transcription factor 24 (TCF-24) and similar proteins. TCF-23, also termed Class A basic helix-loop-helix protein 24 (bHLHa24), is a bHLH transcription factor that is essential for progesterone-dependent decidualization. The mouse homolog is also called ovary, uterus and testis protein (OUT), which is expressed predominantly in the reproductive organs such as the uterus, ovary and testis. It shows an Id-like inhibitory activity and functions as a negative regulator of bHLH factors through the formation of a functionally inactive heterodimeric complex. OUT inhibits the formation of TCF3 and MYOD1 homodimers and heterodimers, but lacks DNA binding activity. OUT is involved in the regulation or modulation of smooth muscle contraction of the uterus during pregnancy and particularly around the time of delivery. It also plays a role in the inhibition of myogenesis. Unlike typical bHLH factors, OUT proteins do not bind E-box (CANNTG) or N-box DNA sequences and inhibit DNA binding of homo- and heterodimers consisting of E12 and MyoD in gel mobility shift assays. TCF-24 is an uncharacterized bHLH transcription factor that shows high sequence similarity with TCF-23.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 28411948  91 RERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd11424   7 RERSRVRTLRTAFQSLQRALPAV--PPDTKLSKLDVLLLASRYIAHLTRKL 55

basic helix-loop-helix (bHLH) domain found in transcription factor 23 (TCF-23) and similar proteins; TCF-23, also termed Class A basic helix-loop-helix protein 24 (bHLHa24), is a bHLH transcription factor that is essential for progesterone-dependent decidualization. The mouse homolog is also called ovary, uterus and testis protein (OUT), which is expressed predominantly in the reproductive organs such as the uterus, ovary and testis. It shows an Id-like inhibitory activity and functions as a negative regulator of bHLH factors through the formation of a functionally inactive heterodimeric complex. OUT inhibits the formation of TCF3 and MYOD1 homodimers and heterodimers, but lacks DNA binding activity. OUT is involved in the regulation or modulation of smooth muscle contraction of the uterus during pregnancy and particularly around the time of delivery. It also plays a role in the inhibition of myogenesis. Unlike typical bHLH factors, OUT proteins do not bind E-box (CANNTG) or N-box DNA sequences and inhibit DNA binding of homo- and heterodimers consisting of E12 and MyoD in gel mobility shift assays.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 28411948  91 RERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd19709   7 RERSRVRTLRQAFLALQAALPSV--PPDTKLSKLDVLVLATSYIAHLTRTLD 56

basic helix-loop-helix (bHLH) domain found in Drosophila melanogaster achaete-scute complex (AS-C) proteins and similar proteins; Drosophila melanogaster AS-C proteins includes lethal of scute (also known as achaete-scute complex protein T3 or AST3), scute (also known as achaete-scute complex protein T4 or AST4), achaete (also known as achaete-scute complex protein T5 or AST5), and asense (also known as achaete-scute complex protein T8 or AST8). They are involved in the determination of the neuronal precursors in the peripheral nervous system and the central nervous system, as well as in sex determination and dosage compensation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 28411948  89 NGRERKRMHDLNLAMDGLREVMPYA----------HGPSvRKLSKIATLLLARNYIlmltSSLEEM 144
Cdd:cd19744   6 NARERNRVKQVNNGFAILRQHIPQSviedltagggRGKS-KKLSKVDTLRMAVEYI----RRLQKL 66

basic helix-loop-helix (bHLH) domain found in musculin, transcription factor 21 (TCF-21) and similar proteins; The family includes two bHLH transcription factors, musculin and transcription factor 21 (TCF-21). Musculin, also termed activated B-cell factor 1 (ABF-1), or Class A basic helix-loop-helix protein 22 (bHLHa22), is a bHLH transcription factor expressed in activated B lymphocytes. It acts as a transcription repressor capable of inhibiting the transactivation capability of TCF3/E47. Musculin may play a role in regulating antigen-dependent B-cell differentiation. The mouse homolog, musculin, is suggested to be a repressor of myogenesis that is expressed in developing muscle and in the spleen. TCF-21, also termed capsulin, or Class A basic helix-loop-helix protein 23 (bHLHa23), or epicardin, or podocyte-expressed 1 (Pod-1), is a bHLH transcription factor expressed specifically in mesodermally-derived cells that surround the epithelium of the developing gastrointestinal, genitourinary and respiratory systems during mouse embryogenesis. It may play a role in the specification or differentiation of one or more subsets of epicardial cell types.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 28411948  89 NGRERKRMHDLNLAMDGLREVMPYAhgPSVRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd11423   6 NARERARMRVLSKAFSRLKTTLPWV--PPDTKLSKLDTLRLAASYIAHLRQIL 56

basic helix-loop-helix (bHLH) domain found in mesogenin-1 (Msgn1) and similar proteins; Msgn1, also termed paraxial mesoderm-specific mesogenin1, or pMesogenin1 (pMsgn1), is a bHLH transcription factor required for maturation and segmentation of paraxial mesoderm. It may regulate the expression of T-box transcription factors essential for mesoderm formation and differentiation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 28411948  83 QLRLKINGRERKRMHDLNLAMDGLREVMPYAHGPSVRKLSKIATLLLARNYILMLTSSLE 142
Cdd:cd18939   7 QRRRKASEREKLRMRTLAEALHTLRNYLPPVYSQRGQPLTKIQTLKCTIQYISELSGLLN 66

basic helix-loop-helix (bHLH) domain found in achaete-scute-like protein 3 (ASCL-3) and similar proteins; ASCL-3, also termed Class A basic helix-loop-helix protein 42 (bHLHa42), or bHLH transcriptional regulator Sgn-1, or achaete-scute homolog 3 (ASH-3), is a bHLH transcription factor specifically localized in the duct cells of the salivary glands. It may act as transcriptional repressor that inhibits myogenesis.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 28411948  87 KINGRERKRMHDLNLAMDGLREVMP--YAHgpsvRKLSKIATLLLARNYILMLTSSL 141
Cdd:cd19745   7 KRNERERQRVKCVNEGYAKLRRHLPqeYSE----KRLSKVETLRAAIKYIKHLQSVL 59