title: Structures of yeast ARF2 and ARL1: distinct roles for the N terminus in the structure and function of ARF family GTPases.
abstract: Structures were determined by x-ray crystallography for two members of the ADP-ribosylation factor (ARF) family of regulatory GTPases, yeast ARF1 and ARL1, and were compared with previously determined structures of human ARF1 and ARF6. These analyses revealed an overall conserved fold but differences in primary sequence and length, particularly in an N-terminal loop, lead to differences in nucleotide and divalent metal binding. Packing of hydrophobic residues is central to the interplay between the N-terminal alpha-helix, switch I, and the interswitch region, which along with differences in surface electrostatics provide explanations for the different biophysical and biochemical properties of ARF and ARF-like proteins.
authors.affiliation: Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322-3050, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Amor
authors.forename: J R
authors.initials: JR
authors.lastname: Horton
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Sullards
authors.forename: D
authors.initials: D
authors.lastname: Ringe
authors.forename: X
authors.initials: X
authors.lastname: Cheng
authors.forename: R A
authors.initials: RA
authors.lastname: Kahn
mesh_terms: D020727:ADP-Ribosylation Factors / Q000737:chemistry*; D000595:Amino Acid Sequence; D001665:Binding Sites; D019281:Dimerization; D005656:Fungal Proteins / Q000737:chemistry*; D020558:GTP Phosphohydrolases / Q000737:chemistry*; D006153:Guanosine Diphosphate / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D029701:Saccharomyces cerevisiae Proteins; D055672:Static Electricity; D013329:Structure-Activity Relationship; D015003:Yeasts / Q000737:chemistry*
chemical_list: D005656:Fungal Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D006153:Guanosine Diphosphate; C097313:ADP-ribosylation factor related proteins; C116686:ARF2 protein, S cerevisiae; D020558:GTP Phosphohydrolases; D020727:ADP-Ribosylation Factors; D008274:Magnesium