Linked Life Data

10085116

Source:http://linkedlifedata.com/resource/pubmed/id/10085116

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1999-4-29
pubmed:abstractText
The sigma subunit of RNA polymerase is a critical factor in positive control of transcription initiation. Primary sigma factors are essential proteins required for vegetative growth, whereas alternative sigma factors mediate transcription in response to various stimuli. Late gene expression during flagellum biosynthesis in Salmonella typhimurium is dependent upon an alternative sigma factor, sigma28, the product of the fliA gene. We have characterized the intermediate complexes formed by sigma28 holoenzyme on the pathway to open complex formation. Interactions with the promoter for the flagellin gene fliC were analyzed using DNase I and KMnO4 footprinting over a range of temperatures. We propose a model in which closed complexes are established in the upstream region of the promoter, including the -35 element, but with little significant contact in the -10 element or downstream regions of the promoter. An isomerization event extends the DNA contacts into the -10 element and the start site, with loss of the most distal upstream contacts accompanied by DNA melting to form open complexes. Melting occurs efficiently even at 16 degrees C. Once open complexes have formed, they are unstable to heparin challenge even in the presence of nucleoside triphosphates, which have been observed to stabilize open complexes at rRNA promoters.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8757-63
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Transcription initiation at the flagellin promoter by RNA polymerase carrying sigma28 from Salmonella typhimurium.
pubmed:affiliation
Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't