Linked Life Data

11073956

Source:http://linkedlifedata.com/resource/pubmed/id/11073956

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-5-23
pubmed:abstractText
The sulfolipid sulfoquinovosyldiacylglycerol is a component of plant photosynthetic membranes and represents one of the few naturally occurring sulfonic acids with detergent properties. Sulfolipid biosynthesis involves the transfer of sulfoquinovose, a 6-deoxy-6-sulfoglucose, from UDP-sulfoquinovose to diacylglycerol. The formation of the sulfonic acid precursor, UDP-sulfoquinovose, from UDP-glucose and a sulfur donor is proposed to be catalyzed by the bacterial SQDB proteins or the orthologous plant SQD1 proteins. To investigate the underlying enzymatic mechanism and to elucidate the de novo synthesis of sulfonic acids in biological systems, we developed an in vitro assay for the recombinant SQD1 protein from Arabidopsis thaliana. Among different possible sulfur donors tested, sulfite led to the formation of UDP-sulfoquinovose in the presence of UDP-glucose and SQD1. An SQD1 T145A mutant showed greatly reduced activity. The UDP-sulfoquinovose formed in this assay was identified by co-chromatography with standards and served as substrate for the sulfolipid synthase associated with spinach chloroplast membranes. Approximate K(m) values of 150 microm for UDP-glucose and 10 microm for sulfite were established for SQD1. Based on our results, we propose that SQD1 catalyzes the formation of UDP-sulfoquinovose from UDP-glucose and sulfite, derived from the sulfate reduction pathway in the chloroplast.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3941-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Recombinant Arabidopsis SQD1 converts udp-glucose and sulfite to the sulfolipid head group precursor UDP-sulfoquinovose in vitro.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1319, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.