ADP-ribosylation factor family; Pfam combines a number of different Prosite families together

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   2 DASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLPDIiacAKQNITTAEISAREGTGLAGV 81
Cdd:pfam00025  76 DSADRDRIEEAKEELHALLNEEELADAPLLILANKQDLPGAMSEAEIRELLGLHEL---KDRPWEIQGCSAVTGEGLDEG 152

                  ....
gi 1331940735  82 LAWL 85
Cdd:pfam00025 153 LDWL 156

ADP-ribosylation factor; Provisional

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   1 MDASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLPDIiacAKQNITTAEISAREGTGLAG 80
Cdd:PTZ00133   92 VDSNDRERIGDAREELERMLSEDELRDAVLLVFANKQDLPNAMSTTEVTEKLGLHSV---RQRNWYIQGCCATTAQGLYE 168

                  ....*...
gi 1331940735  81 VLAWLQAT 88
Cdd:PTZ00133  169 GLDWLSAN 176

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   2 DASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLPDIiacAKQNITTAEISAREGTGLAGV 81
Cdd:cd04159    76 DAADREKLEVAKNELHDLLEKPSLEGIPLLVLGNKNDLPGALSVDELIEQMNLKSI---TDREVSCYSISAKEKTNIDIV 152

                  ....
gi 1331940735  82 LAWL 85
Cdd:cd04159   153 LDWL 156

Sar1 is an essential component of COPII vesicle coats; Sar1 is an essential component of COPII vesicle coats involved in export of cargo from the ER. The GTPase activity of Sar1 functions as a molecular switch to control protein-protein and protein-lipid interactions that direct vesicle budding from the ER. Activation of the GDP to the GTP-bound form of Sar1 involves the membrane-associated guanine nucleotide exchange factor (GEF) Sec12. Sar1 is unlike all Ras superfamily GTPases that use either myristoyl or prenyl groups to direct membrane association and function, in that Sar1 lacks such modification. Instead, Sar1 contains a unique nine-amino-acid N-terminal extension. This extension contains an evolutionarily conserved cluster of bulky hydrophobic amino acids, referred to as the Sar1-N-terminal activation recruitment (STAR) motif. The STAR motif mediates the recruitment of Sar1 to ER membranes and facilitates its interaction with mammalian Sec12 GEF leading to activation.

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                  ....*....|....*....|....*....|....*....|....*....|....
gi 1331940735   2 DASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLP 55
Cdd:cd00879    95 DAADPERFQESKEELDSLLNDEELANVPILILGNKIDKPGAVSEEELREALGLY 148

Arf-like 5 (Arl5) and 8 (Arl8) GTPases; Arl5/Arl8 subfamily. Arl5 (Arf-like 5) and Arl8, like Arl4 and Arl7, are localized to the nucleus and nucleolus. Arl5 is developmentally regulated during embryogenesis in mice. Human Arl5 interacts with the heterochromatin protein 1-alpha (HP1alpha), a nonhistone chromosomal protein that is associated with heterochromatin and telomeres, and prevents telomere fusion. Arl5 may also play a role in embryonic nuclear dynamics and/or signaling cascades. Arl8 was identified from a fetal cartilage cDNA library. It is found in brain, heart, lung, cartilage, and kidney. No function has been assigned for Arl8 to date.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   2 DASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLPD-------IIACakqnittaeiSARE 74
Cdd:cd04153    91 DSTDRERLPLTKEELYKMLAHEDLRKAVLLVLANKQDLKGAMTPAEISESLGLTSirdhtwhIQGC----------CALT 160

                          90
                  ....*....|.
gi 1331940735  75 GTGLAGVLAWL 85
Cdd:cd04153   161 GEGLPEGLDWI 171

Arf-like 3 (Arl3) GTPase; Arl3 (Arf-like 3) is an Arf family protein that differs from most Arf family members in the N-terminal extension. In is inactive, GDP-bound form, the N-terminal extension forms an elongated loop that is hydrophobically anchored into the membrane surface; however, it has been proposed that this region might form a helix in the GTP-bound form. The delta subunit of the rod-specific cyclic GMP phosphodiesterase type 6 (PDEdelta) is an Arl3 effector. Arl3 binds microtubules in a regulated manner to alter specific aspects of cytokinesis via interactions with retinitis pigmentosa 2 (RP2). It has been proposed that RP2 functions in concert with Arl3 to link the cell membrane and the cytoskeleton in photoreceptors as part of the cell signaling or vesicular transport machinery. In mice, the absence of Arl3 is associated with abnormal epithelial cell proliferation and cyst formation.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   1 MDASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLPDII-------ACakqnittaeiSAR 73
Cdd:cd04155    90 IDSADRKRFEEAGQELVELLEEEKLAGVPVLVFANKQDLLTAAPAEEVAEALNLHDIRdrswhiqAC----------SAK 159

                          90
                  ....*....|..
gi 1331940735  74 EGTGLAGVLAWL 85
Cdd:cd04155   160 TGEGLQEGMNWV 171

ADP-ribosylation factor-1 (Arf1) and ADP-ribosylation factor-5 (Arf5); The Arf1-Arf5-like subfamily contains Arf1, Arf2, Arf3, Arf4, Arf5, and related proteins. Arfs1-5 are soluble proteins that are crucial for assembling coat proteins during vesicle formation. Each contains an N-terminal myristoylated amphipathic helix that is folded into the protein in the GDP-bound state. GDP/GTP exchange exposes the helix, which anchors to the membrane. Following GTP hydrolysis, the helix dissociates from the membrane and folds back into the protein. A general feature of Arf1-5 signaling may be the cooperation of two Arfs at the same site. Arfs1-5 are generally considered to be interchangeable in function and location, but some specific functions have been assigned. Arf1 localizes to the early/cis-Golgi, where it is activated by GBF1 and recruits the coat protein COPI. It also localizes to the trans-Golgi network (TGN), where it is activated by BIG1/BIG2 and recruits the AP1, AP3, AP4, and GGA proteins. Humans, but not rodents and other lower eukaryotes, lack Arf2. Human Arf3 shares 96% sequence identity with Arf1 and is believed to generally function interchangeably with Arf1. Human Arf4 in the activated (GTP-bound) state has been shown to interact with the cytoplasmic domain of epidermal growth factor receptor (EGFR) and mediate the EGF-dependent activation of phospholipase D2 (PLD2), leading to activation of the activator protein 1 (AP-1) transcription factor. Arf4 has also been shown to recognize the C-terminal sorting signal of rhodopsin and regulate its incorporation into specialized post-Golgi rhodopsin transport carriers (RTCs). There is some evidence that Arf5 functions at the early-Golgi and the trans-Golgi to affect Golgi-associated alpha-adaptin homology Arf-binding proteins (GGAs).

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   1 MDASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKSLIRLPDiiaCAKQNITTAEISAREGTGLAG 80
Cdd:cd04150    75 VDSNDRERIGEAREELQRMLNEDELRDAVLLVFANKQDLPNAMSAAEVTDKLGLHS---LRNRNWYIQATCATSGDGLYE 151

                  ....*...
gi 1331940735  81 VLAWLQAT 88
Cdd:cd04150   152 GLDWLSNN 159

ADP ribosylation factor 6 (Arf6); Arf6 subfamily. Arf6 (ADP ribosylation factor 6) proteins localize to the plasma membrane, where they perform a wide variety of functions. In its active, GTP-bound form, Arf6 is involved in cell spreading, Rac-induced formation of plasma membrane ruffles, cell migration, wound healing, and Fc-mediated phagocytosis. Arf6 appears to change the actin structure at the plasma membrane by activating Rac, a Rho family protein involved in membrane ruffling. Arf6 is required for and enhances Rac formation of ruffles. Arf6 can regulate dendritic branching in hippocampal neurons, and in yeast it localizes to the growing bud, where it plays a role in polarized growth and bud site selection. In leukocytes, Arf6 is required for chemokine-stimulated migration across endothelial cells. Arf6 also plays a role in down-regulation of beta2-adrenergic receptors and luteinizing hormone receptors by facilitating the release of sequestered arrestin to allow endocytosis. Arf6 is believed to function at multiple sites on the plasma membrane through interaction with a specific set of GEFs, GAPs, and effectors. Arf6 has been implicated in breast cancer and melanoma cell invasion, and in actin remodelling at the invasion site of Chlamydia infection.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1331940735   1 MDASDPTQLSASCVQLLGLLSAEQLAEASVLILFNKIDLPCYMSTEEMKS---LIRLPDIIACAKQNIttaeisAREGTG 77
Cdd:cd04149    84 VDSADRDRIDEARQELHRIINDREMRDALLLVFANKQDLPDAMKPHEIQEklgLTRIRDRNWYVQPSC------ATSGDG 157

                  ....*...
gi 1331940735  78 LAGVLAWL 85
Cdd:cd04149   158 LYEGLTWL 165

Ribosomal interacting GTPase YjeQ/EngC, a circularly permuted subfamily of the Ras GTPases; YjeQ (YloQ in Bacillus subtilis) is a ribosomal small subunit-dependent GTPase; hence also known as RsgA. YjeQ is a late-stage ribosomal biogenesis factor involved in the 30S subunit maturation, and it represents a protein family whose members are broadly conserved in bacteria and have been shown to be essential to the growth of E. coli and B. subtilis. Proteins of the YjeQ family contain all sequence motifs typical of the vast class of P-loop-containing GTPases, but show a circular permutation, with a G4-G1-G3 pattern of motifs as opposed to the regular G1-G3-G4 pattern seen in most GTPases. All YjeQ family proteins display a unique domain architecture, which includes an N-terminal OB-fold RNA-binding domain, the central permuted GTPase domain, and a zinc knuckle-like C-terminal cysteine domain.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1331940735  19 LLSAEQlAEASVLILFNKIDLpcyMSTEEMKSLIRlpdiiACAKQNITTAEISAREGTGLAGVLAWLQ 86
Cdd:cd01854    26 LVAAEA-SGIEPVIVLNKADL---VDDEELEELLE-----IYEKLGYPVLAVSAKTGEGLDELRELLK 84