Linked Life Data

11035017

Source:http://linkedlifedata.com/resource/pubmed/id/11035017

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-3-6
pubmed:abstractText
Among the prokaryotae, the nucleotide ppGpp is a second messenger of physiological stress and starvation. The target of ppGpp is RNA polymerase, where it putatively binds and alters the enzyme's activity. Previous data had implicated the beta-subunit of Escherichia coli RNA polymerase as containing a single ppGpp binding site. In this study, a photocross-linkable derivative of ppGpp, 6-thioguanosine-3',5'-(bis)pyrophosphate (6-thio-ppGpp), was used to localize the ppGpp binding site. In in vitro transcription assays, 6-thio-ppGpp inhibited transcription from the argT promoter identically to bona fide ppGpp. The thio group of 6-thio-ppGpp is directly photoactivatable and is thus a zero-length cross-linker. Cross-linking of RNA polymerase was directed primarily to the beta'-subunit and could be competed efficiently by native ppGpp but not by GTP or GDP. Cyanogen bromide digestion analysis of the cross-linked beta'-subunit was consistent with an extreme N-terminal cross-link. To assess allosteric consequences of ppGpp binding to RNA polymerase, high level trypsin resistance in the presence and absence of ppGpp was monitored. Trypsin digestion of RNA polymerase bound to ppGpp leads to protection of an N-terminal fragment of the beta'-subunit and a C-terminal fragment of the beta-subunit. We propose that the N terminus of beta' together with the C terminus of beta constitute a modular ppGpp binding site.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1220-5
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Binding of the transcription effector ppGpp to Escherichia coli RNA polymerase is allosteric, modular, and occurs near the N terminus of the beta'-subunit.
pubmed:affiliation
Department of Microbiology, Center of Microbial Pathogenesis, State University of New York at Buffalo School of Medicine, Buffalo, New York 14214, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.