GTPase-activating proteins: helping hands to complement an active site.
Stimulation of the intrinsic GTPase activity of GTP-binding proteins by GTPase-activating proteins (GAPs) is a basic principle of GTP-binding-protein downregulation. Recently, the molecular mechanism behind this reaction has been elucidated by studies on Ras and Rho, and their respective GAPs. The basic features involve stabilizing the existing catalytic machinery and supplementing it by an external arginine residue. This represents a novel mechanism for enzyme active-site formation.
Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany.
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Scheffzek
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Ahmadian
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Wittinghofer
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D004789:Enzyme Activation; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D020690:GTPase-Activating Proteins; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D020703:ras GTPase-Activating Proteins
D020690:GTPase-Activating Proteins; D011506:Proteins; D020703:ras GTPase-Activating Proteins; D020558:GTP Phosphohydrolases