PMID:11960029

Citation	Yu, B, Xu, C and Benning, C (2002) Arabidopsis disrupted in SQD2 encoding sulfolipid synthase is impaired in phosphate-limited growth. Proc. Natl. Acad. Sci. U.S.A. 99:5732-7
Abstract	The sulfolipid sulfoquinovosyldiacylglycerol is one of the three nonphosphorous glycolipids that provide the bulk of the structural lipids in photosynthetic membranes of seed plants. Unlike the galactolipids, sulfolipid is anionic at physiological pH because of its 6-deoxy-6-sulfonate-glucose (sulfoquinovose) head group. The biosynthesis of this lipid proceeds in two steps: first, the assembly of UDP-sulfoquinovose from UDP-glucose and sulfite, and second, the transfer of the sulfoquinovose moiety from UDP-sulfoquinovose to diacylglycerol. The first reaction is catalyzed by the SQD1 protein in Arabidopsis. Here we describe the identification of the SQD2 gene of Arabidopsis. We propose that this gene encodes the sulfoquinovosyltransferase catalyzing the second step of sulfolipid biosynthesis. Expression of SQD1 and SQD2 in Escherichia coli reconstituted plant sulfolipid biosynthesis in this bacterium. Insertion of a transfer DNA into this gene in Arabidopsis led to complete lack of sulfolipid in the respective sqd2 mutant. This mutant showed reduced growth under phosphate-limited growth conditions. The results support the hypothesis that sulfolipid can function as a substitute of anionic phospholipids under phosphate-limited growth conditions. Along with phosphatidylglycerol, sulfolipid contributes to maintaining a negatively charged lipid-water interface, which presumably is required for proper function of photosynthetic membranes.
Links	PubMed PMC122840 Online version:10.1073/pnas.082696499
Keywords	Arabidopsis/metabolism; Arabidopsis Proteins/genetics; Arabidopsis Proteins/metabolism; Blotting, Northern; Cell Division; Chlorophyll/metabolism; Cloning, Molecular; DNA, Complementary/metabolism; Dose-Response Relationship, Drug; Escherichia coli/metabolism; Fatty Acids/metabolism; Genetic Complementation Test; Genome, Plant; Hexosyltransferases/genetics; Hexosyltransferases/metabolism; Hydrogen-Ion Concentration; Lipid Metabolism; Lipids; Models, Chemical; Molecular Sequence Data; Mutation; Phosphates/metabolism; Plant Proteins/metabolism; Plasmids/metabolism; Time Factors
edit table

Annotations

Gene product	Qualifier	GO ID	GO term name	Evidence Code	with/from	Aspect	Notes	Status
edit table

References

See Help:References for how to manage references in GONUTS.