title: Structure of zinc-independent sorbitol dehydrogenase from Rhodobacter sphaeroides at 2.4 A resolution.
abstract: Recombinant sorbitol dehydrogenase (SDH) from Rhodobacter sphaeroides has been crystallized in the absence of the cofactor NAD(H) and its structure determined to 2.4 A resolution using molecular replacement (refined R and R free factors of 18.8 and 23.8%, respectively). As expected from the sequence and shown by the conserved fold, SDH can be assigned to the short-chain dehydrogenase/reductase protein family. The cofactor NAD and the substrate sorbitol have been modelled into the structure and the active-site architecture, which displays the highly conserved catalytic tetrad of Asn-Ser-Tyr-Lys residues, is discussed in relation to the enzyme mechanism. This is the first structure of a bacterial SDH belonging to the SDR family.
authors.affiliation: Division of Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland. ansgar.philippsen@unibas.ch
authors.forename: Ansgar
authors.initials: A
authors.lastname: Philippsen
authors.forename: Tilman
authors.initials: T
authors.lastname: Schirmer
authors.forename: Martin A
authors.initials: MA
authors.lastname: Stein
authors.forename: Friedrich
authors.initials: F
authors.lastname: Giffhorn
authors.forename: Jörg
authors.initials: J
authors.lastname: Stetefeld
mesh_terms: D001665:Binding Sites; D003461:Crystallography; D007064:L-Iditol 2-Dehydrogenase / Q000737:chemistry* / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000201:enzymology*; D013012:Sorbitol / Q000378:metabolism
chemical_list: D009243:NAD; D013012:Sorbitol; D007064:L-Iditol 2-Dehydrogenase