[HTML][HTML] Structure of RGS4 bound to AlF4−-activated Giα1: stabilization of the transition state for GTP hydrolysis
JJG Tesmer, DM Berman, AG Gilman, SR Sprang - Cell, 1997 - cell.com
JJG Tesmer, DM Berman, AG Gilman, SR Sprang
Cell, 1997•cell.comRGS proteins are GTPase activators for heterotrimeric G proteins. We report here the 2.8 Å
resolution crystal structure of the RGS protein RGS4 complexed with G iα1–Mg 2+–GDP–AlF
4−. Only the core domain of RGS4 is visible in the crystal. The core domain binds to the
three switch regions of G iα1, but does not contribute catalytic residues that directly interact
with either GDP or AlF 4−. Therefore, RGS4 appears to catalyze rapid hydrolysis of GTP
primarily by stabilizing the switch regions of G iα1, although the conserved Asn-128 from …
resolution crystal structure of the RGS protein RGS4 complexed with G iα1–Mg 2+–GDP–AlF
4−. Only the core domain of RGS4 is visible in the crystal. The core domain binds to the
three switch regions of G iα1, but does not contribute catalytic residues that directly interact
with either GDP or AlF 4−. Therefore, RGS4 appears to catalyze rapid hydrolysis of GTP
primarily by stabilizing the switch regions of G iα1, although the conserved Asn-128 from …
Abstract
RGS proteins are GTPase activators for heterotrimeric G proteins. We report here the 2.8 Å resolution crystal structure of the RGS protein RGS4 complexed with Giα1–Mg2+–GDP–AlF4−. Only the core domain of RGS4 is visible in the crystal. The core domain binds to the three switch regions of Giα1, but does not contribute catalytic residues that directly interact with either GDP or AlF4−. Therefore, RGS4 appears to catalyze rapid hydrolysis of GTP primarily by stabilizing the switch regions of Giα1, although the conserved Asn-128 from RGS4 could also play a catalytic role by interacting with the hydrolytic water molecule or the side chain of Gln-204. The binding site for RGS4 on Giα1 is also consistent with the activity of RGS proteins as antagonists of Gα effectors.
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