title: The structure of rat ADP-ribosylation factor-1 (ARF-1) complexed to GDP determined from two different crystal forms.
abstract: The ARFs are a family of 21,000 M(r) proteins with biological roles in constitutive secretion and activation of phospholipase D. The structure of ARF-1 complexed to GDP determined from two crystal forms reveals a topology that is similar to that of the protein p21 ras with two differences: an additional amino-terminal helix and an extra beta-strand. The Mg2+ ion in ARF-1 displays a five-coordination sphere; this feature is not seen in p21 ras, due to a shift in the relative position of the DXXG motif between the two proteins. The occurrence of a dimer in one crystal form suggests that ARF-1 may dimerize during its biological function. The dimer interface involves a region of the ARF-1 molecule that is analogous to the effector domain in p21 ras and may mediate interactions with its effectors.
authors.affiliation: Glaxo Research & Development, Department of Biomolecular Structure, Stevenage, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Greasley
authors.forename: H
authors.initials: H
authors.lastname: Jhoti
authors.forename: C
authors.initials: C
authors.lastname: Teahan
authors.forename: R
authors.initials: R
authors.lastname: Solari
authors.forename: A
authors.initials: A
authors.lastname: Fensome
authors.forename: G M
authors.initials: GM
authors.lastname: Thomas
authors.forename: S
authors.initials: S
authors.lastname: Cockcroft
authors.forename: B
authors.initials: B
authors.lastname: Bax
mesh_terms: D020727:ADP-Ribosylation Factors; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000737:chemistry; D018360:Crystallography, X-Ray; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008274:Magnesium / Q000378:metabolism; D008956:Models, Chemical; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D016283:Proto-Oncogene Proteins p21(ras) / Q000737:chemistry; D051381:Rats
chemical_list: D006153:Guanosine Diphosphate; D019204:GTP-Binding Proteins; D020727:ADP-Ribosylation Factors; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); D008274:Magnesium