Linked Life Data

1321135

Source:http://linkedlifedata.com/resource/pubmed/id/1321135

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
1992-8-14
pubmed:abstractText
An initial step in the replication of simian virus (SV40) DNA is the ATP-dependent formation of a double hexamer of the SV40 large tumor (T) antigen at the SV40 DNA replication origin. In the absence of DNA, T antigen assembled into hexamers in the presence of magnesium and ATP. Hexameric T antigen was stable and could be isolated by glycerol gradient centrifugation. The ATPase activities of hexameric and monomeric T antigen isolated from parallel glycerol gradients were identical. However, while monomeric T antigen was active in the ATP-dependent binding, untwisting, unwinding, and replication of SV40 origin-containing DNA, hexameric T antigen was inactive in these reactions. Isolated hexamers incubated at 37 degrees C in the presence of ATP remained intact, but dissociated into monomers when incubated at 37 degrees C in the absence of ATP. This dissociation restored the activity of these preparations in the DNA replication reaction, indicating that hexameric T antigen is not permanently inactivated but merely assembled into a nonproductive structure. We propose that the two hexamers of T antigen at the SV40 origin assemble around the DNA from monomer T antigen in solution. This complex untwists the DNA at the origin, melting specific DNA sequences. The resulting single-stranded regions may be utilized by the T antigen helicase activity to initiate DNA unwinding bidirectionally from the origin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14129-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
The simian virus 40 T antigen double hexamer assembles around the DNA at the replication origin.
pubmed:affiliation
Program in Molecular Biology, Sloan-Kettering Cancer Center, New York, New York 10021.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.