Linked Life Data

7559669

Source:http://linkedlifedata.com/resource/pubmed/id/7559669

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
42
pubmed:dateCreated
1995-11-21
pubmed:abstractText
The two type II topoisomerases in Escherichia coli, DNA gyrase and topoisomerase (Topo) IV, share considerable amino acid sequence similarity, yet they have distinctive topoisomerization activities. Only DNA gyrase can supercoil relaxed DNA, whereas during oriC DNA replication in vitro, only Topo IV can support the final stages of replication, processing of the late intermediate and decatenation of the daughter molecules. In order to develop an understanding for the basis of the differential activities of these two enzymes, we have initiated a characterization of Topo IV binding to DNA. We find that unlike gyrase, Topo IV neither constrains DNA in a positive supercoil when it binds nor protects a 150-base pair region of DNA from digestion with micro-coccal nuclease. Consistent with this, DNase I footprinting experiments showed that Topo IV protected a 34-base pair region roughly centered about the topoisomerase-induced cleavage site. In addition, Topo IV preferentially bound supercoiled rather than relaxed DNA. Thus, the DNA binding characteristics of Topo IV are more akin to those of the type II eukaryotic enzymes rather than those of its prokaryotic partner.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25286-90
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The interaction of Escherichia coli topoisomerase IV with DNA.
pubmed:affiliation
Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't