Source:http://linkedlifedata.com/resource/pubmed/id/17298035
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
10
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pubmed:dateCreated |
2007-3-6
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pubmed:abstractText |
LEDGF/p75 is known to enhance the integrase strand transfer activity in vitro, but the underlying mechanism is unclear. Using an integrase assay with a chemiluminescent readout adapted to a 96-well plate format, the effect of LEDGF/p75 on both the 3'-processing and strand transfer steps was analyzed. Integrase inhibitors of the strand transfer reaction remained active in the presence of LEDGF/p75, but displayed 3- to 7-fold higher IC50 values. Our analyses indicate that, in the presence of 150 nM LEDGF/p75, active integrase/donor DNA complexes were increased by 5.3-fold during the 3'-processing step. In addition, these integrase/donor DNA complexes showed a 4.5-fold greater affinity for the target DNA during the subsequent strand transfer step. We also observed a 3.7-fold increase in the rate constant of catalysis of the strand transfer step when 150 nM LEDGF/p75 was present during the 3'-processing step. In contrast, when LEDGF/p75 was added at the beginning of the strand transfer step, no increase in either the concentration of active integrase/donor DNA complex or its rate constant of strand transfer catalysis was observed. This observation suggested that the integrase/donor DNA formed in the absence of LEDGF/p75 became refractory to the stimulatory effect of LEDGF/p75. Instead, this LEDGF/p75 added at the start of the strand transfer step was able to promote the formation of a new cohort of active integrase/donor DNA complexes which became functional with a delay of 45 min after LEDGF/p75 addition. We propose a model whereby LEDGF/p75 can only bind integrase before the latter binds donor DNA whereas donor DNA can engage either free or LEDGF/p75-bound integrase.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/DNA,
http://linkedlifedata.com/resource/pubmed/chemical/HIV Integrase,
http://linkedlifedata.com/resource/pubmed/chemical/Intercellular Signaling Peptides...,
http://linkedlifedata.com/resource/pubmed/chemical/Macromolecular Substances,
http://linkedlifedata.com/resource/pubmed/chemical/lens epithelium-derived growth...
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
13
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pubmed:volume |
46
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2899-908
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pubmed:meshHeading | |
pubmed:year |
2007
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pubmed:articleTitle |
HIV-1 integrase preassembled on donor DNA is refractory to activity stimulation by LEDGF/p75.
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pubmed:affiliation |
Gilead Sciences, 333 Lakeside Drive, Foster City, California 94404, USA.
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pubmed:publicationType |
Journal Article
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