title: Structure of the stand-alone RAM-domain protein from Thermus thermophilus HB8.
abstract: The stand-alone RAM (regulation of amino-acid metabolism) domain protein SraA from Thermus thermophilus HB8 (TTHA0845) was crystallized in the presence of zinc ions. The X-ray crystal structure was determined using a multiple-wavelength anomalous dispersion technique and was refined at 2.4 A resolution to a final R factor of 25.0%. The monomeric structure is a betaalphabetabetaalphabeta fold and it dimerizes mainly through interactions between the antiparallel beta-sheets. Furthermore, five SraA dimers form a ring with external and internal diameters of 70 and 20 A, respectively. This decameric structure is unique compared with the octameric and dodecameric structures found for other stand-alone RAM-domain proteins and the C-terminal RAM domains of Lrp/AsnC-family proteins.
authors.affiliation: RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Nakano
authors.forename: Nobuo
authors.initials: N
authors.lastname: Okazaki
authors.forename: Shinya
authors.initials: S
authors.lastname: Satoh
authors.forename: Koji
authors.initials: K
authors.lastname: Takio
authors.forename: Seiki
authors.initials: S
authors.lastname: Kuramitsu
authors.forename: Akeo
authors.initials: A
authors.lastname: Shinkai
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D019281:Dimerization; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary / Q000235:genetics; D016963:Thermus thermophilus / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins