P-loop containing Nucleoside Triphosphate Hydrolases; Members of the P-loop NTPase domain superfamily are characterized by a conserved nucleotide phosphate-binding motif, also referred to as the Walker A motif (GxxxxGK[S/T], where x is any residue), and the Walker B motif (hhhh[D/E], where h is a hydrophobic residue). The Walker A and B motifs bind the beta-gamma phosphate moiety of the bound nucleotide (typically ATP or GTP) and the Mg2+ cation, respectively. The P-loop NTPases are involved in diverse cellular functions, and they can be divided into two major structural classes: the KG (kinase-GTPase) class which includes Ras-like GTPases and its circularly permutated YlqF-like; and the ASCE (additional strand catalytic E) class which includes ATPase Binding Cassette (ABC), DExD/H-like helicases, 4Fe-4S iron sulfur cluster binding proteins of NifH family, RecA-like F1-ATPases, and ATPases Associated with a wide variety of Activities (AAA). Also included are a diverse set of nucleotide/nucleoside kinase families.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTGADGTSERNFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04127  20 FLYRYTDNKFNPKFITTVGIDFREKRVVYNSQGPDGTSGKAFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 93

Rab GTPase family 27a (Rab27a); The Rab27a subfamily consists of Rab27a and its highly homologous isoform, Rab27b. Unlike most Rab proteins whose functions remain poorly defined, Rab27a has many known functions. Rab27a has multiple effector proteins, and depending on which effector it binds, Rab27a has different functions as well as tissue distribution and/or cellular localization. Putative functions have been assigned to Rab27a when associated with the effector proteins Slp1, Slp2, Slp3, Slp4, Slp5, DmSlp, rabphilin, Dm/Ce-rabphilin, Slac2-a, Slac2-b, Slac2-c, Noc2, JFC1, and Munc13-4. Rab27a has been associated with several human diseases, including hemophagocytic syndrome (Griscelli syndrome or GS), Hermansky-Pudlak syndrome, and choroidermia. In the case of GS, a rare, autosomal recessive disease, a Rab27a mutation is directly responsible for the disorder. When Rab27a is localized to the secretory granules of pancreatic beta cells, it is believed to mediate glucose-stimulated insulin secretion, making it a potential target for diabetes therapy. When bound to JFC1 in prostate cells, Rab27a is believed to regulate the exocytosis of prostate- specific markers. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTGADGTSERNFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04127  20 FLYRYTDNKFNPKFITTVGIDFREKRVVYNSQGPDGTSGKAFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 93

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153     1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:pfam00071  15 LLIRFTQNKFPEEYIPTIGVDFYTKTIEVDGK----------TVKLQIWDTAGQERFRALRPLYYRGADGFLLV 78

GTPase SAR1 family domain [General function prediction only];

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 37789153   1 FLYRYTDGKFN-RKFTTTVGIDFREKRVVYTGTGADgtsernfrvhLQLWDTAGQERFRSLTTAF---FRDAMGFLLM 74
Cdd:COG1100  19 LVNRLVGDIFSlEKYLSTNGVTIDKKELKLDGLDVD----------LVIWDTPGQDEFRETRQFYarqLTGASLYLFV 86

Rab GTPase family 27a (Rab27a); The Rab27a subfamily consists of Rab27a and its highly homologous isoform, Rab27b. Unlike most Rab proteins whose functions remain poorly defined, Rab27a has many known functions. Rab27a has multiple effector proteins, and depending on which effector it binds, Rab27a has different functions as well as tissue distribution and/or cellular localization. Putative functions have been assigned to Rab27a when associated with the effector proteins Slp1, Slp2, Slp3, Slp4, Slp5, DmSlp, rabphilin, Dm/Ce-rabphilin, Slac2-a, Slac2-b, Slac2-c, Noc2, JFC1, and Munc13-4. Rab27a has been associated with several human diseases, including hemophagocytic syndrome (Griscelli syndrome or GS), Hermansky-Pudlak syndrome, and choroidermia. In the case of GS, a rare, autosomal recessive disease, a Rab27a mutation is directly responsible for the disorder. When Rab27a is localized to the secretory granules of pancreatic beta cells, it is believed to mediate glucose-stimulated insulin secretion, making it a potential target for diabetes therapy. When bound to JFC1 in prostate cells, Rab27a is believed to regulate the exocytosis of prostate- specific markers. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTGADGTSERNFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04127  20 FLYRYTDNKFNPKFITTVGIDFREKRVVYNSQGPDGTSGKAFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 93

Ras-related in brain (Rab) family of small guanosine triphosphatases (GTPases); Rab GTPases form the largest family within the Ras superfamily. There are at least 60 Rab genes in the human genome, and a number of Rab GTPases are conserved from yeast to humans. Rab GTPases are small, monomeric proteins that function as molecular switches to regulate vesicle trafficking pathways. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they regulate distinct steps in membrane traffic pathways. In the GTP-bound form, Rab GTPases recruit specific sets of effector proteins onto membranes. Through their effectors, Rab GTPases regulate vesicle formation, actin- and tubulin-dependent vesicle movement, and membrane fusion. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which mask C-terminal lipid binding and promote cytosolic localization. While most unicellular organisms possess 5-20 Rab members, several have been found to possess 60 or more Rabs; for many of these Rab isoforms, homologous proteins are not found in other organisms. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Since crystal structures often lack C-terminal residues, the lipid modification site is not available for annotation in many of the CDs in the hierarchy, but is included where possible.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd00154  16 LLLRFVDNKFSENYKSTIGVDFKSKTIEVDGK----------KVKLQIWDTAGQERFRSITSSYYRGAHGAILV 79

Ras of Complex, Roc, domain of DAPkinase; Roc, or Ras of Complex, proteins are mitochondrial Rho proteins (Miro-1, and Miro-2) and atypical Rho GTPases. Full-length proteins have a unique domain organization, with tandem GTP-binding domains and two EF hand domains (pfam00036) that may bind calcium. They are also larger than classical small GTPases. It has been proposed that they are involved in mitochondrial homeostasis and apoptosis.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153     1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGtgadgtsERNFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:pfam08477  15 LLKRFVDDTFDPKYKSTIGVDFKTKTVLEND-------DNGKKIKLNIWDTAGQERFRSLHPFYYRGAAAALLV 81

Rab GTPase families 8, 10, 13 (Rab8, Rab10, Rab13); Rab8/Sec4/Ypt2 are known or suspected to be involved in post-Golgi transport to the plasma membrane. It is likely that these Rabs have functions that are specific to the mammalian lineage and have no orthologs in plants. Rab8 modulates polarized membrane transport through reorganization of actin and microtubules, induces the formation of new surface extensions, and has an important role in directed membrane transport to cell surfaces. The Ypt2 gene of the fission yeast Schizosaccharomyces pombe encodes a member of the Ypt/Rab family of small GTP-binding proteins, related in sequence to Sec4p of Saccharomyces cerevisiae but closer to mammalian Rab8. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:cd01867  20 LLRFSEDSFNPSFISTIGIDFKIRTIELDGK----------KIKLQIWDTAGQERFRTITTSYYRGAMGIIL 81

Rab GTPase family 26 (Rab26); Rab26 subfamily. First identified in rat pancreatic acinar cells, Rab26 is believed to play a role in recruiting mature granules to the plasma membrane upon beta-adrenergic stimulation. Rab26 belongs to the Rab functional group III, which are considered key regulators of intracellular vesicle transport during exocytosis. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 37789153   1 FLYRYTDGKF-NRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04112  16 LLVRFKDGAFlAGSFIATVGIQFTNKVVTVDGV----------KVKLQIWDTAGQERFRSVTHAYYRDAHALLLL 80

Rab GTPase family 4 (Rab4); Rab4 subfamily. Rab4 has been implicated in numerous functions within the cell. It helps regulate endocytosis through the sorting, recycling, and degradation of early endosomes. Mammalian Rab4 is involved in the regulation of many surface proteins including G-protein-coupled receptors, transferrin receptor, integrins, and surfactant protein A. Experimental data implicate Rab4 in regulation of the recycling of internalized receptors back to the plasma membrane. It is also believed to influence receptor-mediated antigen processing in B-lymphocytes, in calcium-dependent exocytosis in platelets, in alpha-amylase secretion in pancreatic cells, and in insulin-induced translocation of Glut4 from internal vesicles to the cell surface. Rab4 is known to share effector proteins with Rab5 and Rab11. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVvytgtGADGTSernfrVHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:cd04113  17 LHQFIENKFKQDSNHTIGVEFGSRVV-----NVGGKS-----VKLQIWDTAGQERFRSVTRSYYRGAAGALL 78

Rab GTPase family 35 (Rab35); Rab35 is one of several Rab proteins to be found to participate in the regulation of osteoclast cells in rats. In addition, Rab35 has been identified as a protein that interacts with nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) in human cells. Overexpression of NPM-ALK is a key oncogenic event in some anaplastic large-cell lymphomas; since Rab35 interacts with N|PM-ALK, it may provide a target for cancer treatments. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04110  23 LLRFADNTFSGSYITTIGVDFKIRTVEINGE----------RVKLQIWDTAGQERFRTITSTYYRGTHGVIVV 85

Rab GTPase family 33 includes Rab33A and Rab33B; Rab33B/Rab33A subfamily. Rab33B is ubiquitously expressed in mouse tissues and cells, where it is localized to the medial Golgi cisternae. It colocalizes with alpha-mannose II. Together with the other cisternal Rabs, Rab6A and Rab6A', it is believed to regulate the Golgi response to stress and is likely a molecular target in stress-activated signaling pathways. Rab33A (previously known as S10) is expressed primarily in the brain and immune system cells. In humans, it is located on the X chromosome at Xq26 and its expression is down-regulated in tuberculosis patients. Experimental evidence suggests that Rab33A is a novel CD8+ T cell factor that likely plays a role in tuberculosis disease processes. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 37789153   3 YRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFR-SLTTAFFRD 67
Cdd:cd04115  20 YRFCAGRFPERTEATIGVDFRERTVEIDGE----------RIKVQLWDTAGQERFRkSMVQHYYRN 75

Rab GTPase family 11 (Rab11)-like includes Rab11a, Rab11b, and Rab25; Rab11a, Rab11b, and Rab25 are closely related, evolutionary conserved Rab proteins that are differentially expressed. Rab11a is ubiquitously synthesized, Rab11b is enriched in brain and heart and Rab25 is only found in epithelia. Rab11/25 proteins seem to regulate recycling pathways from endosomes to the plasma membrane and to the trans-Golgi network. Furthermore, Rab11a is thought to function in the histamine-induced fusion of tubulovesicles containing H+, K+ ATPase with the plasma membrane in gastric parietal cells and in insulin-stimulated insertion of GLUT4 in the plasma membrane of cardiomyocytes. Overexpression of Rab25 has recently been observed in ovarian cancer and breast cancer, and has been correlated with worsened outcomes in both diseases. In addition, Rab25 overexpression has also been observed in prostate cancer, transitional cell carcinoma of the bladder, and invasive breast tumor cells. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:cd01868  20 LSRFTRNEFNLDSKSTIGVEFATRTIQIDGK----------TIKAQIWDTAGQERYRAITSAYYRGAVGALL 81

Rab GTPase family 7 (Rab7); Rab7 subfamily. Rab7 is a small Rab GTPase that regulates vesicular traffic from early to late endosomal stages of the endocytic pathway. The yeast Ypt7 and mammalian Rab7 are both involved in transport to the vacuole/lysosome, whereas Ypt7 is also required for homotypic vacuole fusion. Mammalian Rab7 is an essential participant in the autophagic pathway for sequestration and targeting of cytoplasmic components to the lytic compartment. Mammalian Rab7 is also proposed to function as a tumor suppressor. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd01862  16 LMNQYVNKKFSNQYKATIGADFLTKEVTVDDR----------LVTLQIWDTAGQERFQSLGVAFYRGA 73

Rab GTPase family 6 (Rab6); Rab6 is involved in microtubule-dependent transport pathways through the Golgi and from endosomes to the Golgi. Rab6A of mammals is implicated in retrograde transport through the Golgi stack, and is also required for a slow, COPI-independent, retrograde transport pathway from the Golgi to the endoplasmic reticulum (ER). This pathway may allow Golgi residents to be recycled through the ER for scrutiny by ER quality-control systems. Yeast Ypt6p, the homolog of the mammalian Rab6 GTPase, is not essential for cell viability. Ypt6p acts in endosome-to-Golgi, in intra-Golgi retrograde transport, and possibly also in Golgi-to-ER trafficking. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 37789153   4 RYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd01861  19 RFMYDTFDNQYQATIGIDFLSKTMYVDDK----------TVRLQLWDTAGQERFRSLIPSYIRDS 73

Rab GTPase family 19 (Rab19); Rab19 subfamily. Rab19 proteins are associated with Golgi stacks. Similarity analysis indicated that Rab41 is closely related to Rab19. However, the function of these Rabs is not yet characterized. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 37789153   4 RYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:cd01864  22 RFKSGTFSERQGNTIGVDFTMKTLEIQGK----------RVKLQIWDTAGQERFRTITQSYYRSANGAII 81

Rab GTPase family 23 (Rab23)-like; Rab23-like subfamily. Rab23 is a member of the Rab family of small GTPases. In mouse, Rab23 has been shown to function as a negative regulator in the sonic hedgehog (Shh) signaling pathway. Rab23 mediates the activity of Gli2 and Gli3, transcription factors that regulate Shh signaling in the spinal cord, primarily by preventing Gli2 activation in the absence of Shh ligand. Rab23 also regulates a step in the cytoplasmic signal transduction pathway that mediates the effect of Smoothened (one of two integral membrane proteins that are essential components of the Shh signaling pathway in vertebrates). In humans, Rab23 is expressed in the retina. Mice contain an isoform that shares 93% sequence identity with the human Rab23 and an alternative splicing isoform that is specific to the brain. This isoform causes the murine open brain phenotype, indicating it may have a role in the development of the central nervous system. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVVYTGTGADgtsernfrVHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd04106  17 IQRFVKGIFTKDYKKTIGVDFLEKQIFLRQSDED--------VRLMLWDTAGQEEFDAITKAYYRGA 75

Rab family protein; Provisional

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153    1 FLYRYTDGKFNRKFTTTVGIDFrekrvvytgtGADGTSERNFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:PLN03108  22 LLLQFTDKRFQPVHDLTIGVEF----------GARMITIDNKPIKLQIWDTAGQESFRSITRSYYRGAAGALLV 85

Rab-related GTPase family includes Rab5 and Rab22; regulates early endosome fusion; The Rab5-related subfamily includes Rab5 and Rab22 of mammals, Ypt51/Ypt52/Ypt53 of yeast, and RabF of plants. The members of this subfamily are involved in endocytosis and endocytic-sorting pathways. In mammals, Rab5 GTPases localize to early endosomes and regulate fusion of clathrin-coated vesicles to early endosomes and fusion between early endosomes. In yeast, Ypt51p family members similarly regulate membrane trafficking through prevacuolar compartments. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 37789153   4 RYTDGKFNRKFTTTVGIDFREKRVVYTGTGadgtsernfrVHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd01860  20 RFVKNEFSENQESTIGAAFLTQTVNLDDTT----------VKFEIWDTAGQERYRSLAPMYYRGA 74

Rab GTPase family 14 (Rab14); Rab14 GTPases are localized to biosynthetic compartments, including the rough ER, the Golgi complex, and the trans-Golgi network, and to endosomal compartments, including early endosomal vacuoles and associated vesicles. Rab14 is believed to function in both the biosynthetic and recycling pathways between the Golgi and endosomal compartments. Rab14 has also been identified on GLUT4 vesicles, and has been suggested to help regulate GLUT4 translocation. In addition, Rab14 is believed to play a role in the regulation of phagocytosis. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04122  19 LHQFTEKKFMADCPHTIGVEFGTRIIEVNGQ----------KIKLQIWDTAGQERFRAVTRSYYRGAAGALMV 81

Rab GTPase families 34 (Rab34) and 36 (Rab36); Rab34/Rab36 subfamily. Rab34, found primarily in the Golgi, interacts with its effector, Rab-interacting lysosomal protein (RILP). This enables its participation in microtubular dynenin-dynactin-mediated repositioning of lysosomes from the cell periphery to the Golgi. A Rab34 (Rah) isoform that lacks the consensus GTP-binding region has been identified in mice. This isoform is associated with membrane ruffles and promotes macropinosome formation. Rab36 has been mapped to human chromosome 22q11.2, a region that is homozygously deleted in malignant rhabdoid tumors (MRTs). However, experimental assessments do not implicate Rab36 as a tumor suppressor that would enable tumor formation through a loss-of-function mechanism. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 37789153   4 RYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd04108  19 RFCKDVFDKNYKATIGVDFEMERFEVLGV----------PFSLQLWDTAGQERFKCIASTYYRGA 73

Septum-promoting GTPase (Spg1); Spg1p. Spg1p (septum-promoting GTPase) was first identified in the fission yeast S. pombe, where it regulates septum formation in the septation initiation network (SIN) through the cdc7 protein kinase. Spg1p is an essential gene that localizes to the spindle pole bodies. When GTP-bound, it binds cdc7 and causes it to translocate to spindle poles. Sid4p (septation initiation defective) is required for localization of Spg1p to the spindle pole body, and the ability of Spg1p to promote septum formation from any point in the cell cycle depends on Sid4p. Spg1p is negatively regulated by Byr4 and cdc16, which form a two-component GTPase activating protein (GAP) for Spg1p. The existence of a SIN-related pathway in plants has been proposed. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd04128  16 LMVKYVEGEFDEEYIQTLGVNFMEKTISIRGT----------EITFSIWDLGGQREFINMLPLVCKDAVAILFM 79

Ran (Ras-related nuclear proteins) /TC4 subfamily of small GTPases; Ran is involved in the active transport of proteins through nuclear pores.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 37789153      1 FLYRYTDGKFNRKFTTTVGIDFrEKRVVYTGTGadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:smart00176  11 FVKRHLTGEFEKKYVATLGVEV-HPLVFHTNRG---------PIRFNVWDTAGQEKFGGLRDGYYIQGQCAIIM 74

GTPase SAR1 family domain [General function prediction only];

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 37789153   1 FLYRYTDGKFN-RKFTTTVGIDFREKRVVYTGTGADgtsernfrvhLQLWDTAGQERFRSLTTAF---FRDAMGFLLM 74
Cdd:COG1100  19 LVNRLVGDIFSlEKYLSTNGVTIDKKELKLDGLDVD----------LVIWDTPGQDEFRETRQFYarqLTGASLYLFV 86

Rho-related protein from plants (Rop)-like; The Rop (Rho-related protein from plants) subfamily plays a role in diverse cellular processes, including cytoskeletal organization, pollen and vegetative cell growth, hormone responses, stress responses, and pathogen resistance. Rops are able to regulate several downstream pathways to amplify a specific signal by acting as master switches early in the signaling cascade. They transmit a variety of extracellular and intracellular signals. Rops are involved in establishing cell polarity in root-hair development, root-hair elongation, pollen-tube growth, cell-shape formation, responses to hormones such as abscisic acid (ABA) and auxin, responses to abiotic stresses such as oxygen deprivation, and disease resistance and disease susceptibility. An individual Rop can have a unique function or an overlapping function shared with other Rop proteins; in addition, a given Rop-regulated function can be controlled by one or multiple Rop proteins. For example, Rop1, Rop3, and Rop5 are all involved in pollen-tube growth; Rop2 plays a role in response to low-oxygen environments, cell-morphology, and root-hair development; root-hair development is also regulated by Rop4 and Rop6; Rop6 is also responsible for ABA response, and ABA response is also regulated by Rop10. Plants retain some of the regulatory mechanisms that are shared by other members of the Rho family, but have also developed a number of unique modes for regulating Rops. Unique RhoGEFs have been identified that are exclusively active toward Rop proteins, such as those containing the domain PRONE (plant-specific Rop nucleotide exchanger). Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 37789153   2 LYRYTDGKFNRKFTTTVGIDFREKRVVytgtgaDGTSernfrVHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:cd04133  18 LISYTSNTFPTDYVPTVFDNFSANVVV------DGNT-----VNLGLWDTAGQEDYNRLRPLSYRGADVFLL 78

Rat sarcoma (Ras) family of small guanosine triphosphatases (GTPases); The Ras family of the Ras superfamily includes classical N-Ras, H-Ras, and K-Ras, as well as R-Ras, Rap, Ral, Rheb, Rhes, ARHI, RERG, Rin/Rit, RSR1, RRP22, Ras2, Ras-dva, and RGK proteins. Ras proteins regulate cell growth, proliferation and differentiation. Ras is activated by guanine nucleotide exchange factors (GEFs) that release GDP and allow GTP binding. Many RasGEFs have been identified. These are sequestered in the cytosol until activation by growth factors triggers recruitment to the plasma membrane or Golgi, where the GEF colocalizes with Ras. Active GTP-bound Ras interacts with several effector proteins: among the best characterized are the Raf kinases, phosphatidylinositol 3-kinase (PI3K), RalGEFs and NORE/MST1. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 37789153   4 RYTDGKFNRKFTTTVGIDFREKRVVytgtgaDGTSernfrVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:cd00876  18 RFVSGEFVEEYDPTIEDSYRKQIVV------DGET-----YTLDILDTAGQEEFSAMRDQYIRNGDGFILV 77

Rab GTPase family 24 (Rab24); Rab24 is distinct from other Rabs in several ways. It exists primarily in the GTP-bound state, having a low intrinsic GTPase activity; it is not efficiently geranyl-geranylated at the C-terminus; it does not form a detectable complex with Rab GDP-dissociation inhibitors (GDIs); and it has recently been shown to undergo tyrosine phosphorylation when overexpressed in vitro. The specific function of Rab24 still remains unknown. It is found in a transport route between ER-cis-Golgi and late endocytic compartments. It is putatively involved in an autophagic pathway, possibly directing misfolded proteins in the ER to degradative pathways. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 37789153   4 RYTDGKF-NRKFTTTVGIDFREKRVVYTGTgadgtsernfRVHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd04118  19 RYVHHRFlVGPYQNTIGAAFVAKRMVVGER----------VVTLGIWDTAGSERYEAMSRIYYRGA 74

small GTP-binding protein domain; Proteins with a small GTP-binding domain recognized by this model include Ras, RhoA, Rab11, translation elongation factor G, translation initiation factor IF-2, tetratcycline resistance protein TetM, CDC42, Era, ADP-ribosylation factors, tdhF, and many others. In some proteins the domain occurs more than once.This model recognizes a large number of small GTP-binding proteins and related domains in larger proteins. Note that the alpha chains of heterotrimeric G proteins are larger proteins in which the NKXD motif is separated from the GxxxxGK[ST] motif (P-loop) by a long insert and are not easily detected by this model. [Unknown function, General]

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 37789153    39 ERNFRVHLQLWDTAGQERFRSLTTAFFRDAMGFLLM 74
Cdd:TIGR00231  46 EDGKTYKFNLLDTAGQEDYDAIRRLYYPQVERSLRV 81

Rat sarcoma (Ras)-like superfamily of small guanosine triphosphatases (GTPases); Ras-like GTPase superfamily. The Ras-like superfamily of small GTPases consists of several families with an extremely high degree of structural and functional similarity. The Ras superfamily is divided into at least four families in eukaryotes: the Ras, Rho, Rab, and Sar1/Arf families. This superfamily also includes proteins like the GTP translation factors, Era-like GTPases, and G-alpha chain of the heterotrimeric G proteins. Members of the Ras superfamily regulate a wide variety of cellular functions: the Ras family regulates gene expression, the Rho family regulates cytoskeletal reorganization and gene expression, the Rab and Sar1/Arf families regulate vesicle trafficking, and the Ran family regulates nucleocytoplasmic transport and microtubule organization. The GTP translation factor family regulates initiation, elongation, termination, and release in translation, and the Era-like GTPase family regulates cell division, sporulation, and DNA replication. Members of the Ras superfamily are identified by the GTP binding site, which is made up of five characteristic sequence motifs, and the switch I and switch II regions.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 37789153   1 FLYRYTDGKFN---RKFTTTVGIDFREKRVVYTGtgadgtsernfrVHLQLWDTAGQERF-----RSLTTAFFRDAMGFL 72
Cdd:cd00882  13 LLNALLGGEVGevsDVPGTTRDPDVYVKELDKGK------------VKLVLVDTPGLDEFgglgrEELARLLLRGADLIL 80

                ..
gi 37789153  73 LM 74
Cdd:cd00882  81 LV 82

Ras of complex proteins (Roc) C-terminal of Roc (COR) domain family; RocCOR (or Roco) protein family is characterized by a superdomain containing a Ras-like GTPase domain, called Roc (Ras of complex proteins), and a characteristic second domain called COR (C-terminal of Roc). A kinase domain and diverse regulatory domains are also often found in Roco proteins. Their functions are diverse; in Dictyostelium discoideum, which encodes 11 Roco proteins, they are involved in cell division, chemotaxis and development, while in human, where 4 Roco proteins (LRRK1, LRRK2, DAPK1, and MFHAS1) are encoded, these proteins are involved in epilepsy and cancer. Mutations in LRRK2 (leucine-rich repeat kinase 2) are known to cause familial Parkinson's disease.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 37789153   9 KFNRKFTTTVGIDFREKRVvytgtgadgTSERNFRVHLQLWDTAGQERFRSlTTAFF 65
Cdd:cd09914  25 KFDGDESSTHGINVQDWKI---------PAPERKKIRLNVWDFGGQEIYHA-THQFF 71

Rab GTPase-like family 2 (Rab-like2); RabL2 (Rab-like2) subfamily. RabL2s are novel Rab proteins identified recently which display features that are distinct from other Rabs, and have been termed Rab-like. RabL2 contains RabL2a and RabL2b, two very similar Rab proteins that share > 98% sequence identity in humans. RabL2b maps to the subtelomeric region of chromosome 22q13.3 and RabL2a maps to 2q13, a region that suggests it is also a subtelomeric gene. Both genes are believed to be expressed ubiquitously, suggesting that RabL2s are the first example of duplicated genes in human proximal subtelomeric regions that are both expressed actively. Like other Rab-like proteins, RabL2s lack a prenylation site at the C-terminus. The specific functions of RabL2a and RabL2b remain unknown. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization.

                        10        20
                ....*....|....*....|....*
gi 37789153  44 VHLQLWDTAGQERFRSLTTAFFRDA 68
Cdd:cd04124  49 ILVDFWDTAGQERFQTMHASYYHKA 73

Small GTPase of the Ras superfamily; ill-defined subfamily; SMART predicts Ras-like small GTPases of the ARF, RAB, RAN, RAS, and SAR subfamilies. Others that could not be classified in this way are predicted to be members of the small GTPase superfamily without predictions of the subfamily.

                           10        20        30
                   ....*....|....*....|....*....|
gi 37789153     44 VHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:smart00010  50 CLLDILDTAGQEEFSAMRDQYMRTGEGFLL 79

Rab GTPase family 20 (Rab20); Rab20 is one of several Rab proteins that appear to be restricted in expression to the apical domain of murine polarized epithelial cells. It is expressed on the apical side of polarized kidney tubule and intestinal epithelial cells, and in non-polarized cells. It also localizes to vesico-tubular structures below the apical brush border of renal proximal tubule cells and in the apical region of duodenal epithelial cells. Rab20 has also been shown to colocalize with vacuolar H+-ATPases (V-ATPases) in mouse kidney cells, suggesting a role in the regulation of V-ATPase traffic in specific portions of the nephron. It was also shown to be one of several proteins whose expression is upregulated in human myelodysplastic syndrome (MDS) patients. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 37789153   1 FLYRYTDGKFNRKFTTTVGIDFREKRVVYtgtgadgtsernfrvHLQLWDTAGQERFRSLTTAFFRDAMGFLL 73
Cdd:cd04126  16 LLHRYMERRFKDTVSTVGGAFYLKQWGPY---------------NISIWDTAGREQFHGLGSMYCRGAAAVIL 73

Arf-like 9 (Arl9) and 10 (Arl10) GTPases; Arl10-like subfamily. Arl9/Arl10 was identified from a human cancer-derived EST dataset. No functional information about the subfamily is available at the current time, but crystal structures of human Arl10b and Arl10c have been solved.

                        10        20
                ....*....|....*....|....
gi 37789153  43 RVHLQLWDTAGQERFRSLTTAFFR 66
Cdd:cd04159  43 NVTIKVWDLGGQPRFRSMWERYCR 66