Linked Life Data

1313943

Source:http://linkedlifedata.com/resource/pubmed/id/1313943

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-5-14
pubmed:abstractText
Two DNA topoisomerases control the level of negative supercoiling in bacterial cells. DNA gyrase introduces supercoils, and DNA topoisomerase I prevents supercoiling from reaching unacceptably high levels. Perturbations of supercoiling are corrected by the substrate preferences of these topoisomerases with respect to DNA topology and by changes in expression of the genes encoding the enzymes. However, supercoiling changes when the growth environment is altered in ways that also affect cellular energetics. The ratio of [ATP] to [ADP], to which gyrase is sensitive, may be involved in the response of supercoiling to growth conditions. Inside cells, supercoiling is partitioned into two components, superhelical tension and restrained supercoils. Shifts in superhelical tension elicited by nicking or by salt shock do not rapidly change the level of restrained supercoiling. However, a steady-state change in supercoiling caused by mutation of topA does alter both tension and restrained supercoils. This communication between the two compartments may play a role in the control of supercoiling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
425-33
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Control of bacterial DNA supercoiling.
pubmed:affiliation
Public Health Research Institute, New York, New York 10016.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Review