Download MendeleyCrystal structure of SQD1, an enzyme involved in the biosynthesis of the plant sulfolipid headgroup donor UDP-sulfoquinovose.
Mulichak, A.M., Theisen, M.J., Essigmann, B., Benning, C., Garavito, R.M.(1999) Proc Natl Acad Sci U S A 96: 13097-13102
- PubMed: 10557279
- DOI: https://doi.org/10.1073/pnas.96.23.13097
- Primary Citation of Related Structures:
1QRR - PubMed Abstract:
The SQD1 enzyme is believed to be involved in the biosynthesis of the sulfoquinovosyl headgroup of plant sulfolipids, catalyzing the transfer of SO(3)(-) to UDP-glucose. We have determined the structure of the complex of SQD1 from Arabidopsis thaliana with NAD(+) and the putative substrate UDP-glucose at 1.6-A resolution. Both bound ligands are completely buried within the binding cleft, along with an internal solvent cavity which is the likely binding site for the, as yet, unidentified sulfur-donor substrate. SQD1 is a member of the short-chain dehydrogenase/reductase (SDR) family of enzymes, and its structure shows a conservation of the SDR catalytic residues. Among several highly conserved catalytic residues, Thr-145 forms unusually short hydrogen bonds with both susceptible hydroxyls of UDP-glucose. A His side chain may also be catalytically important in the sulfonation.
Organizational Affiliation:
Department of Biochemistry, Michigan State University, East Lansing, MI 48824-1319, USA.
