Linked Life Data

7929078

Source:http://linkedlifedata.com/resource/pubmed/id/7929078

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
39
pubmed:dateCreated
1994-10-27
pubmed:abstractText
We have examined the molecular mechanism that enables the T4 bacteriophage DNA polymerase holoenzyme to synthesize DNA processively on the leading strand of the replication fork for many minutes, while allowing an identical holoenzyme on the lagging strand to recycle from one Okazaki fragment to the next in less than 4 s. We use a perfect hairpin helix of 15 base pairs to mimic the encounter of the polymerase with the end of a previously synthesized Okazaki fragment. Polymerase dissociation is monitored during the stall at the hairpin helix by the addition of excess T4 gene 32 protein (SSB protein), which rapidly melts the helix and allows a stalled polymerase molecule to continue DNA synthesis. In the accompanying paper, we show that polymerase holoenzyme dissociation is slow (half-life of 2.5 min) when this enzyme is stalled by nucleotide omission (Hacker, K. J., and Alberts, B. M. (1994) J. Biol. Chem. 269, 24209-24220). In contrast, the holoenzyme dissociates with a half-life of 1 s after hitting the hairpin helix, a rate sufficient to allow efficient polymerase recycling on the lagging strand in vivo. We conclude that, upon completing each Okazaki fragment, the holoenzyme senses an encounter with duplex DNA and then switches to a state that rapidly dissociates.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24221-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
The rapid dissociation of the T4 DNA polymerase holoenzyme when stopped by a DNA hairpin helix. A model for polymerase release following the termination of each Okazaki fragment.
pubmed:affiliation
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't