Linked Life Data

6343804

Source:http://linkedlifedata.com/resource/pubmed/id/6343804

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1983-7-29
pubmed:abstractText
Certain strains suppress the temperature-sensitivity caused by ssb-1, which encodes a mutant ssDNA binding protein (SSB). At 42 degrees C, such strains are extremely UV-sensitive, degrade their DNA extensively after UV irradiation, and are deficient in UV mutability and UV induction of recA protein synthesis. We transduced recC22, which eliminates Exonuclease V activity, and recAo281, which causes operator-constitutive synthesis of recA protein, into such an ssb-1 strain. Both double mutants degraded their DNA extensively at 42 degrees C after UV irradiation, and both were even more UV-sensitive than the ssb-1 single mutant. We conclude that one or more nucleases other than Exonuclease V degrades DNA in the ssb recC strain, and that recA protein, even if synthesized copiously, can function efficiently in recombinational DNA repair and in control of post-UV DNA degradation only if normal SSB is also present. Pretreatment with nalidixic acid at 30 degrees C restored normal UV mutability at 42 degrees C, but did not increase UV resistance, in an ssb-1 strain. Another ssb allele, ssb-113, which blocks SOS induction at 30 degrees C, increases spontaneous mutability more than tenfold. The ssb-113 allele was transduced into the SOS-constitutive recA730 strain SC30. This double mutant expressed the same elevated spontaneous and UV-induced mutability at 30 degrees C as the ssb+ recA730 strain, and was three times more UV-resistant than its ssb-113 recA+ parent. We conclude that ssb-1 at 42 degrees C and ssb-113 at 30 degrees C block UV-induced activation of recA protease, but that neither allele interferes with subsequent steps in SOS-mediated mutagenesis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
190
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
92-100
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
DNA degradation, UV sensitivity and SOS-mediated mutagenesis in strains of Escherichia coli deficient in single-strand DNA binding protein: effects of mutations and treatments that alter levels of Exonuclease V or recA protein.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't