Linked Life Data

7961451

Source:http://linkedlifedata.com/resource/pubmed/id/7961451

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1994-12-16
pubmed:abstractText
The repressor protein of bacteriophage 434 binds to DNA as a dimer of identical subunits. Its strong dimerization is mediated by the carboxyl-terminal domain. Cooperative interactions between the C-terminal domains of two repressor dimers bound at adjacent sites can stabilize protein-DNA complexes formed with low-affinity binding sites. We have constructed a plasmid, pCT1, which directs the overproduction of the carboxyl-terminal domain of 434 repressor. The protein encoded by this plasmid is called CT-1. Cells transformed with pCT1 are unable to be lysogenized by wild-type 434 phage, whereas control cells are lysogenized at an efficiency of 1 to 5%. The CT-1-mediated interference with lysogen formation presumably results from formation of heteromeric complexes between the phage-encoded repressor and the plasmid-encoded carboxyl-terminal domain fragment. These heteromers are unable to bind DNA and thereby inhibit the repressor's activity in promoting lysogen formation. Two lines of evidence support this conclusion. First, DNase I footprinting experiments show that at a 2:1 ratio of CT-1 to intact 434 repressor, purified CT-1 protein prevents the formation of complexes between 434 repressor and its OR1 binding site. Second, cross-linking experiments reveal that only a specific heterodimeric complex forms between CT-1 and intact 434 repressor. This latter observation indicates that CT-1 interferes with 434 repressor-operator complex formation by preventing dimerization and not by altering the conformation of the DNA-bound repressor dimer. Our other evidence is also consistent with this suggestion. We have used deletion analysis in an attempt to define the region which mediates the 434 repressor-CT-1 interaction. CT-1 proteins which have more than the last 14 amino acids removed are unable to interfere with 434 repressor action in vivo.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-1567879, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-159452, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-1731202, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-2038061, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-2531662, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-2973565, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-3187531, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-3553960, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-4033758, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-609095, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-6369323, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-6554278, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-7047751, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-8152379, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-8254659, http://linkedlifedata.com/resource/pubmed/commentcorrection/7961451-8369279
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9193
pubmed:author
pubmed:issnType
Print
pubmed:volume
176
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6907-14
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Expression, purification, and functional characterization of the carboxyl-terminal domain fragment of bacteriophage 434 repressor.
pubmed:affiliation
Department of Biological Sciences, State University of New York at Buffalo 14260-1300.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.