Open AccessX‐ray crystal structure and small‐angle X‐ray scattering of sheep liver sorbitol dehydrogenase
Author(s) -
Yennawar Hemant,
Møller Magda,
Gillilan Richard,
Yennawar Neela
Publication year - 2011
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444911007815
Subject(s) - tetramer , sorbitol dehydrogenase , crystallography , dehydrogenase , chemistry , substrate (aquarium) , sorbitol , oxidoreductase , small angle x ray scattering , monomer , protein quaternary structure , stereochemistry , enzyme , scattering , biochemistry , biology , organic chemistry , protein subunit , physics , ecology , optics , gene , polymer
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 I 222 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.