title: Residues forming a hydrophobic pocket in ARF3 are determinants of GDP dissociation and effector interactions.
abstract: Three residues of human ADP-ribosylation factor 3 (ARF3) (F51, W66 and Y81) cluster into a hydrophobic pocket in the inactive, GDP-bound protein. Disruption of the hydrophobic pocket with mutations at these residues increased the rate of GDP dissociation and association, but not always that of GTPgammaS. Several of the same mutants were found to be defective, often selectively, in binding different ARF effectors in two-hybrid assays. These results highlight three features of these hydrophobic residues in regulating (1) the rate of GDP dissociation, (2) the conformational changes that promote GTP binding and (3) their role in binding target proteins.
authors.affiliation: Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322-3050, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kuai
authors.forename: R A
authors.initials: RA
authors.lastname: Kahn
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000737:chemistry* / Q000378:metabolism; D020727:ADP-Ribosylation Factors / Q000737:chemistry* / Q000378:metabolism*; D019943:Amino Acid Substitution; D001665:Binding Sites; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C116687:ARF3 protein, human; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors