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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2002-4-15
pubmed:abstractText
DNA replication in bacteria is performed by a specialized multicomponent replicase, the DNA polymerase III holoenzyme, that consist of three essential components: a polymerase, the beta sliding clamp processivity factor, and the DnaX complex clamp-loader. We report here the assembly of the minimal functional holoenzyme from Thermus thermophilus (Tth), an extreme thermophile. The minimal holoenzyme consists of alpha (pol III catalytic subunit), beta (sliding clamp processivity factor), and the essential DnaX (tau/gamma), delta and delta' components of the DnaX complex. We show with purified recombinant proteins that these five components are required for rapid and processive DNA synthesis on long single-stranded DNA templates. Subunit interactions known to occur in DNA polymerase III holoenzyme from mesophilic bacteria including delta-delta' interaction, deltadelta'-tau/gamma complex formation, and alpha-tau interaction, also occur within the Tth enzyme. As in mesophilic holoenzymes, in the presence of a primed DNA template, these subunits assemble into a stable initiation complex in an ATP-dependent manner. However, in contrast to replicative polymerases from mesophilic bacteria, Tth holoenzyme is efficient only at temperatures above 50 degrees C, both with regard to initiation complex formation and processive DNA synthesis. The minimal Tth DNA polymerase III holoenzyme displays an elongation rate of 350 bp/s at 72 degrees C and a processivity of greater than 8.6 kilobases, the length of the template that is fully replicated after a single association event.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13401-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
DNA polymerase III holoenzyme from Thermus thermophilus identification, expression, purification of components, and use to reconstitute a processive replicase.
pubmed:affiliation
Replidyne, Inc., Denver, Colorado 80206, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.