Source:http://linkedlifedata.com/resource/pubmed/id/15561706
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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
2005-2-7
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pubmed:abstractText |
DNA polymerase beta (pol beta) and flap endonuclease 1 (FEN1) are key players in pol beta-mediated long-patch base excision repair (LP-BER). It was proposed that this type of LP-BER is accomplished through FEN1 removal of a 2- to 11-nucleotide flap created by pol beta strand displacement DNA synthesis. To understand how these enzymes might cooperate during LP-BER, we characterized purified human pol beta DNA synthesis by utilizing various BER intermediates, including single-nucleotide-gapped DNA, nicked DNA, and nicked DNA with various lengths of flaps all with a 5'-terminal tetrahydrofuran (THF) residue. We observed that nicked DNA and nicked-THF flap DNA were poor substrates for pol beta-mediated DNA synthesis; yet, DNA synthesis was strongly stimulated by purified human FEN1. FEN1 did not improve pol beta substrate binding. FEN1 cleavage activity was required for the stimulation, suggesting that FEN1 removed a barrier to pol beta DNA synthesis. In addition, FEN1 cleavage on both nicked and nicked-THF flap DNA resulted in a one-nucleotide gapped DNA molecule that was an ideal substrate for pol beta. This study demonstrates that pol beta cooperates with FEN1 to remove DNA damage via a "Hit and Run" mechanism, involving alternating short gap production by FEN1 and gap filling by pol beta, rather than through coordinated formation and removal of a strand-displaced flap.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
4
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pubmed:volume |
280
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3665-74
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pubmed:meshHeading |
pubmed-meshheading:15561706-DNA,
pubmed-meshheading:15561706-DNA Polymerase beta,
pubmed-meshheading:15561706-DNA Repair,
pubmed-meshheading:15561706-Electrophoretic Mobility Shift Assay,
pubmed-meshheading:15561706-Flap Endonucleases,
pubmed-meshheading:15561706-Humans,
pubmed-meshheading:15561706-Substrate Specificity
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pubmed:year |
2005
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pubmed:articleTitle |
DNA polymerase beta and flap endonuclease 1 enzymatic specificities sustain DNA synthesis for long patch base excision repair.
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pubmed:affiliation |
Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
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pubmed:publicationType |
Journal Article
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