Linked Life Data

11188759

Source:http://linkedlifedata.com/resource/pubmed/id/11188759

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-1-8
pubmed:abstractText
The bacteriophage T4 AsiA protein inhibits transcription from host and phage early promoters and is required, along with the T4 MotA protein, for activation of phage middle promoters. During infection, AsiA is found in a tight association with the sigma70 subunit of RNA polymerase. We show that AsiA binds rapidly to free sigma70 at either 4 degrees C or 30 degrees C to form an AsiA-sigma70 complex that with core efficiently reconstitutes the AsiA-inhibited RNA polymerase. In contrast, AsiA does not inhibit transcription after a 15 minute incubation with RNA polymerase holoenzyme at 4 degrees C, and at 30 degrees C an incubation of several minutes is required to inhibit most of the polymerase. We show that the heat step needed for AsiA is not the formation of an active AsiA protein. However, it is consistent with the momentary dissociation of holoenzyme to give free sigma70 and core. Our results indicate that AsiA is either unable to access holoenzyme directly or does so very slowly. Efficient generation of the AsiA-inhibited RNA polymerase requires that AsiA first binds to free sigma70 and then the AsiA-sigma70 complex binds to core to form the Asi-A-inhibited polymerase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
304
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
731-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Efficient inhibition of Escherichia coli RNA polymerase by the bacteriophage T4 AsiA protein requires that AsiA binds first to free sigma70.
pubmed:affiliation
Laboratory of Molecular and Cellular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA. dhinton@helix.nih.gov
pubmed:publicationType
Journal Article