G proteins, effectors and GAPs: structure and mechanism.
G proteins from a diverse family of regulatory GTPases which, in the GTP-bound state, bind to and activate downstream effectors. Structures of Ras homologs bound to effector domains have revealed mechanisms by which G proteins couple GTP binding to effector activation and achieve specificity. Complexes between structurally unrelated GTPase-activating proteins with complementary G proteins suggest common mechanisms by which GTP hydrolysis is stimulated via direct interactions with conformationally labile switch regions of the G protein.
Sprang
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Howard Hughes Medical Institute, University of Texas, Southwestern Medical Center, Dallas 75235-9050, USA. sprang@howie.swmed.edu
D001665:Binding Sites; D020558:GTP Phosphohydrolases / Q000737:chemistry / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D020690:GTPase-Activating Proteins; D006160:Guanosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras) / Q000737:chemistry / Q000378:metabolism; D020703:ras GTPase-Activating Proteins; D018631:ras Proteins / Q000737:chemistry* / Q000378:metabolism
D020690:GTPase-Activating Proteins; D011506:Proteins; D020703:ras GTPase-Activating Proteins; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins