1e0s
small G protein Arf6-GDP
Structural highlights
FunctionARF6_HUMAN GTP-binding protein involved in protein trafficking; regulates endocytic recycling and cytoskeleton remodeling. May modulate vesicle budding and uncoating within the Golgi apparatus. Functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. Involved in the regulation of dendritic spine development (By similarity). Contributes to the regulation of dendritic branching and filopodia extension.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedArf6 is an isoform of Arf that localizes at the periphery of the cell where it has an essential role in endocytotic pathways. Its function does not overlap with that of Arf1, although the two proteins share approximately 70% sequence identity and they have switch regions, whose conformation depends on the nature of the guanine nucleotide, with almost identical sequences. The crystal structure of Arf6-GDP at 2.3 A shows that it has a conformation similar to that of Arf1-GDP, which cannot bind membranes with high affinity. Significantly, the switch regions of Arf6 deviate by 2-5 A from those of Arf1. These differences are a consequence of the shorter N-terminal linker of Arf6 and of discrete sequence changes between Arf6 and Arf1. Mutational analysis shows that one of the positions which differs between Arf1 and Arf6 affects the configuration of the nucleotide binding site and thus the nucleotide binding properties of the Arf variant. Altogether, our results provide a structural basis for understanding how Arf1 and Arf6 can be distinguished by their guanine nucleotide exchange factors and suggest a model for the nucleotide/membrane cycle of Arf6. Structure of Arf6-GDP suggests a basis for guanine nucleotide exchange factors specificity.,Menetrey J, Macia E, Pasqualato S, Franco M, Cherfils J Nat Struct Biol. 2000 Jun;7(6):466-9. PMID:10881192[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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