Linked Life Data

10411758

Source:http://linkedlifedata.com/resource/pubmed/id/10411758

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-9-2
pubmed:abstractText
It has been known for over half a century that anoxygenic photosynthetic bacteria maximally synthesize their photosystems in the absence of oxygen. During the last decade, it has become clear that this regulation is largely at the transcriptional level, with photosynthesis genes expressed only under anaerobic conditions. We describe here in vitro reconstitution of activation and repression of three photosynthesis promoters, bch (bacteriochlorophyll biosynthesis), puc (light-harvesting II apoproteins) and puf (reaction centre and light-harvesting I apoproteins) using purified transcription factors and RNA polymerase from Rhodobacter capsulatus. Previous genetic results have indicated that each of these three promoters is differentially regulated by three key regulators: CrtJ acting as a repressor of bch and puc and the two-component regulators RegA/RegB, which are activators of puc and puf. These regulators are distinct from those that mediate oxygen control in enteric bacteria. Our in vitro studies show that these purified regulators directly control the expression of the housekeeping RNA polymerase at these promoters. High-level basal expression of the bch promoter is shown to be repressed by CrtJ. The puc promoter is activated by the RegB-phosphorylated RegA protein and additionally repressed by CrtJ. At the puc promoter, CrtJ effectively competes for promoter binding with RegA, while at the bch promoter, repression appears to be by competition for the RNA polymerase binding site. In contrast to what has been suggested previously, the RegA-activated puf promoter is demonstrated as being recognized by the housekeeping RNA polymerase. We also discuss evidence that RegA approximately P activation of the puc and puf promoters involves recruitment of RNA polymerase by different modes of protein-protein interaction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
429-37
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:10411758-Bacterial Proteins, pubmed-meshheading:10411758-Base Sequence, pubmed-meshheading:10411758-DNA, Bacterial, pubmed-meshheading:10411758-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:10411758-Gene Expression Regulation, Bacterial, pubmed-meshheading:10411758-Light-Harvesting Protein Complexes, pubmed-meshheading:10411758-Molecular Sequence Data, pubmed-meshheading:10411758-Phosphoprotein Phosphatases, pubmed-meshheading:10411758-Photosynthesis, pubmed-meshheading:10411758-Photosynthetic Reaction Center Complex Proteins, pubmed-meshheading:10411758-Promoter Regions, Genetic, pubmed-meshheading:10411758-Protein Kinases, pubmed-meshheading:10411758-Rhodobacter capsulatus, pubmed-meshheading:10411758-Trans-Activators, pubmed-meshheading:10411758-Transcription, Genetic
pubmed:year
1999
pubmed:articleTitle
In vitro activation and repression of photosynthesis gene transcription in Rhodobacter capsulatus.
pubmed:affiliation
Department of Biology, Washington University, One Brookings Drive, St Louis, MO 63130, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.