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
                 ....*....|....*....|....*....|....*....|....*....
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd01861    1 HKLVFLGDQSVGKTSIITRFMYDTFDNQYQATIGIDFLSKTMYVDDKTV 49

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
                 ....*....|....*....|....*....|....*....|....*....
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd01861    1 HKLVFLGDQSVGKTSIITRFMYDTFDNQYQATIGIDFLSKTMYVDDKTV 49

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
                  ....*....|....*....|....*....|....*....|....*
gi 344030202   15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLED 59
Cdd:pfam08477   1 KVVLLGDSGVGKTSLLKRFVDDTFDPKYKSTIGVDFKTKTVLEND 45

GTPase SAR1 family domain [General function prediction only];

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 344030202  11 LRKFKLVFLGEQSVGKTSLITRFMYDSFDN-TYQATIGIDFLSKTMYLEDRTL 62
Cdd:COG1100    1 MGEKKIVVVGTGGVGKTSLVNRLVGDIFSLeKYLSTNGVTIDKKELKLDGLDV 53

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
                 ....*....|....*....|....*....|....*....|....*....
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd01861    1 HKLVFLGDQSVGKTSIITRFMYDTFDNQYQATIGIDFLSKTMYVDDKTV 49

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
                 ....*....|....*....|....*....|....*....|....*...
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRT 61
Cdd:cd00154    1 FKIVLIGDSGVGKTSLLLRFVDNKFSENYKSTIGVDFKSKTIEVDGKK 48

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
                  ....*....|....*....|....*....|....*....|....*..
gi 344030202   15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRT 61
Cdd:pfam00071   1 KLVLVGDGGVGKSSLLIRFTQNKFPEEYIPTIGVDFYTKTIEVDGKT 47

Rab GTPase families 18 (Rab18) and 32 (Rab32); Rab38/Rab32 subfamily. Rab32 and Rab38 are members of the Rab family of small GTPases. Human Rab32 was first identified in platelets but it is expressed in a variety of cell types, where it functions as an A-kinase anchoring protein (AKAP). Rab38 has been shown to be melanocyte-specific. 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
                 ....*....|....*....|....*....|....*....|....*....|.
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTLFR 64
Cdd:cd04107    1 FKVLVIGDLGVGKTSIIKRYVHGVFSQHYKATIGVDFALKVIEWDPNTVVR 51

Rab GTPase family 21 (Rab21); The localization and function of Rab21 are not clearly defined, with conflicting data reported. Rab21 has been reported to localize in the ER in human intestinal epithelial cells, with partial colocalization with alpha-glucosidase, a late endosomal/lysosomal marker. More recently, Rab21 was shown to colocalize with and affect the morphology of early endosomes. In Dictyostelium, GTP-bound Rab21, together with two novel LIM domain proteins, LimF and ChLim, has been shown to regulate 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
                 ....*....|....*....|....*....|....*....|....*....
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd04123    1 FKVVLLGEGRVGKTSLVLRYVENKFNEKHESTTQASFFQKTVNIGGKRI 49

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
                 ....*....|....*....|....*....|....*....|....*....
gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSF-DNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd04118    2 KVVMLGKESVGKTSLVERYVHHRFlVGPYQNTIGAAFVAKRMVVGERVV 50

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
                 ....*....|....*....|....*....|....*....|....*
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLE 58
Cdd:cd01867    4 FKLLLIGDSGVGKSCLLLRFSEDSFNPSFISTIGIDFKIRTIELD 48

Rab GTPase family 3 contains Rab3A, Rab3B, Rab3C and Rab3D; The Rab3 subfamily contains Rab3A, Rab3B, Rab3C, and Rab3D. All four isoforms were found in mouse brain and endocrine tissues, with varying levels of expression. Rab3A, Rab3B, and Rab3C localized to synaptic and secretory vesicles; Rab3D was expressed at high levels only in adipose tissue, exocrine glands, and the endocrine pituitary, where it is localized to cytoplasmic secretory granules. Rab3 appears to control Ca2+-regulated exocytosis. The appropriate GDP/GTP exchange cycle of Rab3A is required for Ca2+-regulated exocytosis to occur, and interaction of the GTP-bound form of Rab3A with effector molecule(s) is widely believed to be essential for this process. Functionally, most studies point toward a role for Rab3 in the secretion of hormones and neurotransmitters. 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
                 ....*....|....*....|....*....|....*....|....*..
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDR 60
Cdd:cd01865    2 FKLLIIGNSSVGKTSFLFRYADDSFTSAFVSTVGIDFKVKTVYRNDK 48

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
                 ....*....|....*....|....*....|....*....|....*...
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRT 61
Cdd:cd01868    4 FKIVLIGDSGVGKSNLLSRFTRNEFNLDSKSTIGVEFATRTIQIDGKT 51

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
                 ....*....|....*....|....*....|....*....|....*
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLE 58
Cdd:cd04110    7 FKLLIIGDSGVGKSSLLLRFADNTFSGSYITTIGVDFKIRTVEIN 51

GTPase SAR1 family domain [General function prediction only];

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 344030202  11 LRKFKLVFLGEQSVGKTSLITRFMYDSFDN-TYQATIGIDFLSKTMYLEDRTL 62
Cdd:COG1100    1 MGEKKIVVVGTGGVGKTSLVNRLVGDIFSLeKYLSTNGVTIDKKELKLDGLDV 53

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
                 ....*....|....*....|....*....|....*.
gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDF 50
Cdd:cd04108    2 KVIVVGDLSVGKTCLINRFCKDVFDKNYKATIGVDF 37

Rab GTPase; Provisional

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:PLN03110  13 FKIVLIGDSGVGKSNILSRFTRNEFCLESKSTIGVEFATRTLQVEGKTV 61

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
                 ....*....|....*....|....*....|....*....|....*...
gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd04128    2 KIGLLGDAQIGKTSLMVKYVEGEFDEEYIQTLGVNFMEKTISIRGTEI 49

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
                 ....*....|....*....|....*....|....*....|....*
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLE 58
Cdd:cd01864    4 FKIILIGDSNVGKTCVVQRFKSGTFSERQGNTIGVDFTMKTLEIQ 48

Rab GTPase family 39 (Rab39); Found in eukaryotes, Rab39 is mainly found in epithelial cell lines, but is distributed widely in various human tissues and cell lines. It is believed to be a novel Rab protein involved in regulating Golgi-associated vesicular transport during cellular endocytosis. 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
                 ....*....|....*....|....*....|....*....|....*..
gi 344030202  13 KFKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLED 59
Cdd:cd04111    2 QFRLIVIGDSTVGKSSLLKRFTEGRFAEVSDPTVGVDFFSRLIEIEP 48

Rab GTPase family J-like (RabJ-like); RJLs are found in many protists and as chimeras with C-terminal DNAJ domains in deuterostome metazoa. They are not found in plants, fungi, and protostome metazoa, suggesting a horizontal gene transfer between protists and deuterostome metazoa. RJLs lack any known membrane targeting signal and contain a degenerate phosphate/magnesium-binding 3 (PM3) motif, suggesting an impaired ability to hydrolyze GTP. 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
                 ....*....|....*....|....*....|....*....|....*..
gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRT 61
Cdd:cd04119    2 KVISMGNSGVGKSCIIKRYCEGRFVSKYLPTIGIDYGVKKVSVRNKE 48

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 344030202  13 KFKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTLFR 64
Cdd:cd09914    1 EAKLMLVGQGGVGKTSLCKQLIGEKFDGDESSTHGINVQDWKIPAPERKKIR 52

Ras homology family (Rho) of small guanosine triphosphatases (GTPases); Members of the Rho (Ras homology) family include RhoA, Cdc42, Rac, Rnd, Wrch1, RhoBTB, and Rop. There are 22 human Rho family members identified currently. These proteins are all involved in the reorganization of the actin cytoskeleton in response to external stimuli. They also have roles in cell transformation by Ras in cytokinesis, in focal adhesion formation and in the stimulation of stress-activated kinase. These various functions are controlled through distinct effector proteins and mediated through a GTP-binding/GTPase cycle involving three classes of regulating proteins: GAPs (GTPase-activating proteins), GEFs (guanine nucleotide exchange factors), and GDIs (guanine nucleotide dissociation inhibitors). 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. Since crystal structures often lack C-terminal residues, this feature is not available for annotation in many of the CDs in the hierarchy.

                         10        20        30
                 ....*....|....*....|....*....|..
gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATI 46
Cdd:cd00157    2 KIVVVGDGAVGKTCLLISYTTNKFPTEYVPTV 33

Rem, Rem2, Rad, Gem/Kir (RGK) subfamily of Ras GTPases; RGK subfamily. The RGK (Rem, Rem2, Rad, Gem/Kir) subfamily of Ras GTPases are expressed in a tissue-specific manner and are dynamically regulated by transcriptional and posttranscriptional mechanisms in response to environmental cues. RGK proteins bind to the beta subunit of L-type calcium channels, causing functional down-regulation of these voltage-dependent calcium channels, and either termination of calcium-dependent secretion or modulation of electrical conduction and contractile function. Inhibition of L-type calcium channels by Rem2 may provide a mechanism for modulating calcium-triggered exocytosis in hormone-secreting cells, and has been proposed to influence the secretion of insulin in pancreatic beta cells. RGK proteins also interact with and inhibit the Rho/Rho kinase pathway to modulate remodeling of the cytoskeleton. Two characteristics of RGK proteins cited in the literature are N-terminal and C-terminal extensions beyond the GTPase domain typical of Ras superfamily members. The N-terminal extension is not conserved among family members; the C-terminal extension is reported to be conserved among the family and lack the CaaX prenylation motif typical of membrane-associated Ras proteins. However, a putative CaaX motif has been identified in the alignment of the C-terminal residues of this CD.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 344030202  14 FKLVFLGEQSVGKTSLITRFM--------YD-SFDNTYQATIGIDFLSKTMYLED 59
Cdd:cd04148    1 YRVVLLGDSGVGKSSLANIFTagvyedsaYEaSGDDTYERTVSVDGEEATLVVYD 55

GTP-binding nuclear protein Ran; Provisional

                         10        20        30
                 ....*....|....*....|....*....|....*.
gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGID 49
Cdd:PLN03071  14 FKLVIVGDGGTGKTTFVKRHLTGEFEKKYEPTIGVE 49

Ras homolog enriched in striatum (Rhes) and activator of G-protein signaling 1 (Dexras1/AGS1); This subfamily includes Rhes (Ras homolog enriched in striatum) and Dexras1/AGS1 (activator of G-protein signaling 1). These proteins are homologous, but exhibit significant differences in tissue distribution and subcellular localization. Rhes is found primarily in the striatum of the brain, but is also expressed in other areas of the brain, such as the cerebral cortex, hippocampus, inferior colliculus, and cerebellum. Rhes expression is controlled by thyroid hormones. In rat PC12 cells, Rhes is farnesylated and localizes to the plasma membrane. Rhes binds and activates PI3K, and plays a role in coupling serpentine membrane receptors with heterotrimeric G-protein signaling. Rhes has recently been shown to be reduced under conditions of dopamine supersensitivity and may play a role in determining dopamine receptor sensitivity. Dexras1/AGS1 is a dexamethasone-induced Ras protein that is expressed primarily in the brain, with low expression levels in other tissues. Dexras1 localizes primarily to the cytoplasm, and is a critical regulator of the circadian master clock to photic and nonphotic input. 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.

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gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGiDFLSKTMYL 57
Cdd:cd04143    1 YRMVVLGASKVGKTAIVSRFLGGRFEEQYTPTIE-DFHRKLYSI 43

Ral (Ras-like) family containing highly homologous RalA and RalB; The Ral (Ras-like) subfamily consists of the highly homologous RalA and RalB. Ral proteins are believed to play a crucial role in tumorigenesis, metastasis, endocytosis, and actin cytoskeleton dynamics. Despite their high sequence similarity (>80% sequence identity), nonoverlapping and opposing functions have been assigned to RalA and RalBs in tumor migration. In human bladder and prostate cancer cells, RalB promotes migration while RalA inhibits it. A Ral-specific set of GEFs has been identified that are activated by Ras binding. This RalGEF activity is enhanced by Ras binding to another of its target proteins, phosphatidylinositol 3-kinase (PI3K). Ral effectors include RLIP76/RalBP1, a Rac/cdc42 GAP, and the exocyst (Sec6/8) complex, a heterooctomeric protein complex that is involved in tethering vesicles to specific sites on the plasma membrane prior to exocytosis. In rat kidney cells, RalB is required for functional assembly of the exocyst and for localizing the exocyst to the leading edge of migrating cells. In human cancer cells, RalA is required to support anchorage-independent proliferation and RalB is required to suppress apoptosis. RalA has been shown to localize to the plasma membrane while RalB is localized to the intracellular vesicles. 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.

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gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATI 46
Cdd:cd04139    1 HKVIMVGSGGVGKSALTLQFMYDEFVEDYEPTK 33

Rab GTPase family 12 (Rab12); Rab12 was first identified in canine cells, where it was localized to the Golgi complex. The specific function of Rab12 remains unknown, and inconsistent results about its cellular localization have been reported. More recent studies have identified Rab12 associated with post-Golgi vesicles, or with other small vesicle-like structures but not with the Golgi complex. 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. 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.

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gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd04120    2 QVIIIGSRGVGKTSLMERFTDDTFCEACKSTVGVDFKIKTVELRGKKI 49

Ras Homolog Enriched in Brain (RheB) is a small GTPase; Rheb (Ras Homolog Enriched in Brain) subfamily. Rheb was initially identified in rat brain, where its expression is elevated by seizures or by long-term potentiation. It is expressed ubiquitously, with elevated levels in muscle and brain. Rheb functions as an important mediator between the tuberous sclerosis complex proteins, TSC1 and TSC2, and the mammalian target of rapamycin (TOR) kinase to stimulate cell growth. TOR kinase regulates cell growth by controlling nutrient availability, growth factors, and the energy status of the cell. TSC1 and TSC2 form a dimeric complex that has tumor suppressor activity, and TSC2 is a GTPase activating protein (GAP) for Rheb. The TSC1/TSC2 complex inhibits the activation of TOR kinase through Rheb. Rheb has also been shown to induce the formation of large cytoplasmic vacuoles in a process that is dependent on the GTPase cycle of Rheb, but independent of the TOR kinase, suggesting Rheb plays a role in endocytic trafficking that leads to cell growth and cell-cycle progression. 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.

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gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATI 46
Cdd:cd04137    3 KIAVLGSRSVGKSSLTVQFVEGHFVESYYPTI 34

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.

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gi 344030202  15 KLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDRTL 62
Cdd:cd04124    2 KIILLGDSAVGKSKLVERFLMDGYEPQQLSTYALTLYKHNAKFEGKTI 49

Rab family protein; Provisional

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gi 344030202  14 FKLVFLGEQSVGKTSLITRFMYDSFDNTYQATIGIDFLSKTMYLEDR 60
Cdd:PLN03108   7 FKYIIIGDTGVGKSCLLLQFTDKRFQPVHDLTIGVEFGARMITIDNK 53