title: Crystal structure of Bacillus subtilis S-adenosylmethionine:tRNA ribosyltransferase-isomerase.
abstract: The enzyme S-adenosylmethionine:tRNA ribosyltransferase-isomerase (QueA) is involved in the biosynthesis of the hypermodified tRNA nucleoside queuosine. It is unprecedented in nature as it uses the cofactor S-adenosylmethionine as the donor of a ribosyl group. We have determined the crystal structure of Bacillus subtilis QueA at a resolution of 2.9A. The structure reveals two domains representing a 6-stranded beta-barrel and an alpha beta alpha-sandwich, respectively. All amino acid residues invariant in the QueA enzymes of known sequence cluster at the interface of the two domains indicating the localization of the substrate binding region and active center. Comparison of the B. subtilis QueA structure with the structure of QueA from Thermotoga maritima suggests a high domain flexibility of this enzyme.
authors.affiliation: Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Grimm
authors.forename: Ralf
authors.initials: R
authors.lastname: Ficner
authors.forename: Tanja
authors.initials: T
authors.lastname: Sgraja
authors.forename: Peter
authors.initials: P
authors.lastname: Haebel
authors.forename: Gerhard
authors.initials: G
authors.lastname: Klebe
authors.forename: Klaus
authors.initials: K
authors.lastname: Reuter
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D001665:Binding Sites; D003198:Computer Simulation; D003461:Crystallography; D004789:Enzyme Activation; D007535:Isomerases / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity
chemical_list: C082572:S-adenosylmethionine - tRNA ribosyltransferase-isomerase; D007535:Isomerases