Goldberg J (1999) Structural and functional analysis of the ARF1-ARFGAP complex reveals a role for coatomer in GTP hydrolysis. Cell 96(6):893-902
Abstract: The crystal structure of the complex of ARF1 GTPase bound to GDP and the catalytic domain of ARF GTPase-activating protein (ARFGAP) has been determined at 1.95 A resolution. The ARFGAP molecule binds to switch 2 and helix alpha3 to orient ARF1 residues for catalysis, but it supplies neither arginine nor other amino acid side chains to the GTPase active site. In the complex, the effector-binding region appears to be unobstructed, suggesting that ARFGAP could stimulate GTP hydrolysis while ARF1 maintains an interaction with its effector, the coatomer complex of COPI-coated vesicles. Biochemical experiments show that coatomer directly participates in the GTPase reaction, accelerating GTP hydrolysis a further 1000-fold in an ARFGAP-dependent manner. Thus, a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats.
|Status: Published||Type: Journal Article||PubMed ID: 10102276|
Topics addressed in this paper
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|Protein Sequence Features|
|Protein/Nucleic Acid Structure|