Linked Life Data

15522872

Source:http://linkedlifedata.com/resource/pubmed/id/15522872

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-12-31
pubmed:abstractText
The viability of the topA mutants lacking DNA topoisomerase I was thought to depend on the presence of compensatory mutations in Escherichia coli but not Salmonella typhimurium or Shigella flexneri. This apparent discrepancy in topA requirements in different bacteria prompted us to reexamine the topA requirements in E. coli. We find that E. coli strains bearing topA mutations, introduced into the strains by DNA-mediated gene replacement, are viable at 37 or 42 degrees C without any compensatory mutations. These topA(-) cells exhibit cold sensitivity in their growth, however, and this cold sensitivity phenotype appears to be caused by excessive negative supercoiling of intracellular DNA. In agreement with previous results (Zhu, Q., Pongpech, P., and DiGate, R. J. (2001) Proc. Natl. Acad. Sci. U. S. A. 98, 9766-9771), E. coli cells lacking both type IA DNA topoisomerases I and III are found to be nonviable, indicating that the two type IA enzymes share a critical cellular function.
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
7
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
355-60
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Viability of Escherichia coli topA mutants lacking DNA topoisomerase I.
pubmed:affiliation
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural