IUBMB Enzyme Nomenclature


Accepted name: UDP-sulfoquinovose synthase

Reaction: UDP-α-D-sulfoquinovopyranose + H2O = UDP-α-D-glucose + sulfite

For diagram of the reaction, click here

Other name(s): sulfite:UDP-glucose sulfotransferase; UDPsulfoquinovose synthase

Systematic name: UDP-6-sulfo-6-deoxyglucose sulfohydrolase

Comments: Requires NAD+, which appears to oxidize UDP-α-D-glucose to UDP-4-dehydroglucose, which dehydrates to UDP-4-dehydro-6-deoxygluc-5-enose, to which sulfite is added. The reaction is completed when the substrate is rehydrogenated at C-4. The enzyme from Arabidopsis thaliana is specific for UDP-Glc and sulfite.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB CAS registry number:


1. Essigmann, B., Gler, S., Narang, R.A., Linke, D. and Benning, C. Phosphate availability affects the thylakoid lipid composition and the expression of SQD1, a gene required for sulfolipid biosynthesis in Arabidopsis thaliana. Proc. Natl. Acad. Sci. USA 95 (1998) 1950-1955. [PMID: 9465123]

2. Essigmann, B., Hespenheide, B.M., Kuhn, L.A. and Benning, C. Prediction of the active-site structure and NAD+ binding in SQD1, a protein essential for sulfolipid biosynthesis in Arabidopsis. Arch. Biochem. Biophys. 369 (1999) 30-41. [PMID: 10462438]

3. Mulichak, A.M., Theisen, M.J., Essigmann, B., Benning, C. and Garavito, R.M. Crystal structure of SQD1, an enzyme involved in the biosynthesis of the plant sulfolipid headgroup donor UDP-sulfoquinovose. Proc. Natl. Acad. Sci. USA 96 (1999) 13097-13102. [PMID: 10557279]

4. Sanda, S., Leustek, T., Theisen, M., Garavito, R.M. and Benning, C. Recombinant Arabidopsis SQD1 converts UDP-glucose and sulfite to the sulfolipid head group precursor UDP-sulfoquinovose in vitro. J. Biol. Chem. 276 (2001) 3941-3946. [PMID: 11073956]

[EC created 2001, modified 2010]

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