Linked Life Data

19759020

Source:http://linkedlifedata.com/resource/pubmed/id/19759020

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
45
pubmed:dateCreated
2009-11-2
pubmed:abstractText
Clamp loaders assemble sliding clamps onto 3' primed sites for DNA polymerases. Clamp loaders are thought to be specific for a 3' primed site, and unable to bind a 5' site. We demonstrate here that the Escherichia coli gamma complex clamp loader can load the beta clamp onto a 5' primed site, although with at least 20-fold reduced efficiency relative to loading at a 3' primed site. Preferential clamp loading at a 3' site does not appear to be due to DNA binding, as the clamp loader forms an avid complex with beta at a 5' site. Preferential loading at a 3' versus a 5' site occurs at the ATP hydrolysis step, needed to close the ring around DNA. We also address DNA structural features that are recognized for preferential loading at a 3' site. Although the single-stranded template strand extends in opposite directions from 3' and 5' primed sites, thus making it a favorite candidate for distinguishing between 3' and 5' sites, the single-strand polarity at a primed template junction does not determine 3' site selection for clamp loading. Instead, we find that clamp loader recognition of a 3' site lies in the duplex portion of the primed site, not the single-strand portion. We present evidence that the beta clamp facilitates its own loading specificity for a 3' primed site. Implications to eukaryotic clamp loader complexes are proposed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
6
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31473-83
pubmed:dateRevised
2010-11-9
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
The clamp loader assembles the beta clamp onto either a 3' or 5' primer terminus: the underlying basis favoring 3' loading.
pubmed:affiliation
Howard Hughes Medical Institute, Rockefeller University, New York, New York 10065, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural