title: X-ray crystal structure and small-angle X-ray scattering of sheep liver sorbitol dehydrogenase.
abstract: The X-ray crystal structure of sheep liver sorbitol dehydrogenase (slSDH) has been determined using the crystal structure of human sorbitol dehydrogenase (hSDH) as a molecular-replacement model. slSDH crystallized in space group I222 with one monomer in the asymmetric unit. A conserved tetramer that superposes well with that seen in hSDH (despite belonging to a different space group) and obeying the 222 crystal symmetry is seen in slSDH. An acetate molecule is bound in the active site, coordinating to the active-site zinc through a water molecule. Glycerol, a substrate of slSDH, also occupies the substrate-binding pocket together with the acetate designed by nature to fit large polyol substrates. The substrate-binding pocket is seen to be in close proximity to the tetramer interface, which explains the need for the structural integrity of the tetramer for enzyme activity. Small-angle X-ray scattering was also used to identify the quaternary structure of the tetramer of slSDH in solution.
authors.affiliation: Department of Biochemistry and Molecular Biology and Huck Institutes of Life Sciences, Pennsylvania State University, 8 Althouse Laboratory, University Park, PA 16802, USA.
authors.forename: Hemant
authors.initials: H
authors.lastname: Yennawar
authors.forename: Magda
authors.initials: M
authors.lastname: Møller
authors.forename: Richard
authors.initials: R
authors.lastname: Gillilan
authors.forename: Neela
authors.initials: N
authors.lastname: Yennawar
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D006801:Humans; D007064:L-Iditol 2-Dehydrogenase / Q000737:chemistry*; D008099:Liver / Q000201:enzymology*; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D053838:Scattering, Small Angle; D012756:Sheep / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D007064:L-Iditol 2-Dehydrogenase