Linked Life Data

9545328

Source:http://linkedlifedata.com/resource/pubmed/id/9545328

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1998-5-21
pubmed:abstractText
Transcription initiation by Escherichia coli RNA polymerase at most promoters is associated with a reiterative synthesis and release of short abortive RNA products. We have investigated the mechanism of abortive RNA synthesis by using holoenzymes containing mutant sigma70 subunits with changes in region 3 (S506F and P504L), which reduce the ratio of abortive to full-length products. Binary complexes formed by these mutant enzymes at a modified lambdaPR promoter contained a smaller fraction of open complexes than for normal polymerase, suggesting an involvement of region 3 in melting duplex DNA or in maintenance of the open complex. The half-lives of the majority of binary complexes formed by the mutant enzymes were less than 1 min, in contrast to 30 min for the wild-type complexes. The time courses of transcription and pulse-labeling assays showed that moribund complexes, which generate only abortive products (Kubori, T., and Shimamoto, N. (1996) J. Mol. Biol. 256, 449-457), were formed by the mutant enzymes. However, they accumulated to a lesser extent than for the wild-type enzyme, due both to faster dissociation and conversion into inactive complexes. This is the main cause of the low degree of abortive transcription displayed by the mutant enzymes on this promoter.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9872-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Reduction in abortive transcription from the lambdaPR promoter by mutations in region 3 of the sigma70 subunit of Escherichia coli RNA polymerase.
pubmed:affiliation
Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka-411, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't