Linked Life Data

16407212

Source:http://linkedlifedata.com/resource/pubmed/id/16407212

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2006-2-27
pubmed:abstractText
Reverse gyrase is a hyperthermophile-specific enzyme that can positively supercoil DNA concomitant with ATP hydrolysis. However, the DNA supercoiling activity is inefficient and requires an excess amount of enzyme relative to DNA. We report here several activities that reverse gyrase can efficiently mediate with a substoichiometric amount of enzyme. In the presence of a nucleotide cofactor, reverse gyrase can readily relax negative supercoils, but not the positive ones, from a plasmid DNA substrate. Reverse gyrase can completely relax positively supercoiled DNA, provided that the DNA substrate contains a single-stranded bubble. Reverse gyrase efficiently anneals complementary single-stranded circles. A substoichiometric amount of reverse gyrase can insert positive supercoils into DNA with a single-stranded bubble, in contrast to plasmid DNA substrate. We have designed a novel method based on phage-mid DNA vectors to prepare a circular DNA substrate containing a single-stranded bubble with defined length and sequence. With these bubble DNA substrates, we demonstrated that efficient positive supercoiling by reverse gyrase requires a bubble size larger than 20 nucleotides. The activities of annealing single-stranded DNA circles and positive supercoiling of bubble substrate demonstrate that reverse gyrase can function as a DNA renaturase. These biochemical activities also suggest that reverse gyrase can have an important biological function in sensing and eliminating unpaired regions in the genome of a hyperthermophilic organism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5640-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Reverse gyrase functions as a DNA renaturase: annealing of complementary single-stranded circles and positive supercoiling of a bubble substrate.
pubmed:affiliation
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA. hsieh@biochem.duke.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural