3bh7
From Proteopedia
Crystal structure of the RP2-Arl3 complex bound to GDP-AlF4
Structural highlights
FunctionARL3_MOUSE Small GTP-binding protein which cycles between an inactive GDP-bound and an active GTP-bound form, and the rate of cycling is regulated by guanine nucleotide exchange factors (GEF) and GTPase-activating proteins (GAP). Required for normal cytokinesis and cilia signaling. Required for targeting proteins such as NPHP3 to the ciliary membrane by releasing myristoylated NPHP3 from UNC119B cargo adapter into the cilium (By similarity). Requires assistance from GTPase-activating proteins (GAPs) like RP2 and PDE6D, in order to cycle between inactive GDP-bound and active GTP-bound forms.[1] [2] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe retinitis pigmentosa 2 (RP2) gene is responsible for a particular variant of X chromosome-linked eye disease. Previously, RP2 was shown to bind the GTP form of the small G protein Arf-like 3 (Arl3), thus qualifying as an effector. Here we present the Arl3-GppNHp-RP2 complex structure, which shows features resembling complexes with GTPase-activating proteins (GAPs). Biochemical analysis showing a 90,000-fold stimulation of the GTPase reaction together with the structure of an Arl3-GDP-AlF4--RP2 transition state complex showed that RP2 is an efficient GAP for Arl3, with structural features similar to other GAPs. Furthermore, the effect of mutations in patients with retinitis pigmentosa correlated with their effect on catalysis, in particular the mutation of the arginine finger of RP2. The cognate G protein-GAP pair is conserved in yeast as Cin4-Cin2, and the ability of RP2 to act as a GAP can be correlated with its ability to complement a CIN2-deletion phenotype. The retinitis pigmentosa 2 gene product is a GTPase-activating protein for Arf-like 3.,Veltel S, Gasper R, Eisenacher E, Wittinghofer A Nat Struct Mol Biol. 2008 Apr;15(4):373-80. Epub 2008 Mar 23. PMID:18376416[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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