title: The structure of an N11A mutant of the G-protein domain of FeoB.
abstract: The uptake of ferrous iron in prokaryotes is mediated by the G-protein-coupled membrane protein FeoB. The protein contains two N-terminal soluble domains that are together called `NFeoB'. One of these is a G-protein domain, and GTP hydrolysis by this domain is essential for iron transport. The GTPase activity of NFeoB is accelerated in the presence of potassium ions, which bind at a site adjacent to the nucleotide. One of the ligands at the potassium-binding site is a conserved asparagine residue, which corresponds to Asn11 in Streptococcus thermophilus NFeoB. The structure of an N11A S. thermophilus NFeoB mutant has been determined and refined to a resolution of 1.85 Å; the crystals contained a mixture of mant-GDP-bound and mant-GMP-bound protein. The structure demonstrates how the use of a derivatized nucleotide in cocrystallization experiments can facilitate the growth of diffraction-quality crystals.
authors.affiliation: School of Molecular Bioscience, University of Sydney, NSW 2006, Australia.
authors.forename: Miriam Rose
authors.initials: MR
authors.lastname: Ash
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Maher
authors.forename: J Mitchell
authors.initials: JM
authors.lastname: Guss
authors.forename: Mika
authors.initials: M
authors.lastname: Jormakka
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009154:Mutation; D017434:Protein Structure, Tertiary; D048249:Streptococcus thermophilus / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins