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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
50
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pubmed:dateCreated |
2007-12-13
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pubmed:abstractText |
Helicases are enzymes that couple ATP hydrolysis to the unwinding of double-stranded (ds) nucleic acids. The bacteriophage T4 helicase (gp41) is a hexameric helicase that promotes DNA replication within a highly coordinated protein complex termed the replisome. Despite recent progress, the gp41 unwinding mechanism and regulatory interactions within the replisome remain unclear. Here we use a single tethered DNA hairpin as a real-time reporter of gp41-mediated dsDNA unwinding and single-stranded (ss) DNA translocation with 3-base pair (bp) resolution. Although gp41 translocates on ssDNA as fast as the in vivo replication fork ( approximately 400 bp/s), its unwinding rate extrapolated to zero force is much slower ( approximately 30 bp/s). Together, our results have two implications: first, gp41 unwinds DNA through a passive mechanism; second, this weak helicase cannot efficiently unwind the T4 genome alone. Our results suggest that important regulations occur within the replisome to achieve rapid and processive replication.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-10899133,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-10966472,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-11207360,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-11395406,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-11735390,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-11889086,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-12023254,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-12484983,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-12574500,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-1466817,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-14754162,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-15079074,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-15123793,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-15381422,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-15561144,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-15728347,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-15902262,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-16397502,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-16670085,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-16855583,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-16935883,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-16935884,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-17506634,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-17604719,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-17656723,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-17709749,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-2538456,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-4882615,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-6110662,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-6288720,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-7706292,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8107085,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8596951,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8628994,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8662873,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8663273,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8811178,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-8962073,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-9342340,
http://linkedlifedata.com/resource/pubmed/commentcorrection/18077411-9671724
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
1091-6490
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pubmed:author |
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pubmed:issnType |
Electronic
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pubmed:day |
11
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pubmed:volume |
104
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
19790-5
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
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pubmed:year |
2007
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pubmed:articleTitle |
Real-time observation of bacteriophage T4 gp41 helicase reveals an unwinding mechanism.
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pubmed:affiliation |
Laboratoire de Physique Statistique, Ecole Normale Supérieure, Centre National de la Recherche Scientifique-UMR8550, 24 Rue Lhomond, 75005 Paris, France. tlionnet@aecom.yu.edu
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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