Intermolecular disintegration and intramolecular strand transfer activities of wild-type and mutant HIV-1 integrase.
We report the activities of HIV integrase protein on a novel DNA substrate, consisting of a pair of gapped duplex molecules. Integrase catalyzed an intermolecular disintegration reaction that requires positioning of a pair of the gapped duplexes in a configuration that resembles the intgration intermediate. However, the major reaction resulted from an intramolecular reaction involving a single gapped duplex, giving rise to a hairpin. Surprisingly, a deletion mutant of integrase that lacks both the amino and carboxyl terminal regions still catalyzed the intermolecular disintegration reaction, but supported only a very low level of the intramolecular reaction. The central core region of integrase is therefore sufficient to both bind the gapped duplex DNA and juxtapose a pair of such molecules through protein-protein interactions. We suggest that the branched DNA structures of the previously reported disintegration substrate, and the intermolecular disintegration substrate described here, assist in stabilizing protein-protein interactions that otherwise require the amino and carboxy terminal regions of integrase.
Mazumder
A
A
Laboratory of Molecular Pharmacology, NCI, Rockville, MD 20892.
Engelman
A
A
Craigie
R
R
Fesen
M
M
Pommier
Y
Y
D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004254:DNA Nucleotidyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004279:DNA, Viral / Q000737:chemistry / Q000378:metabolism; D017353:Gene Deletion; D015497:HIV-1 / Q000201:enzymology* / Q000235:genetics; D019426:Integrases; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D004279:DNA, Viral; D004247:DNA; D004254:DNA Nucleotidyltransferases; D019426:Integrases