title: Position-specific suppression and enhancement of HIV-1 integrase reactions by minor groove benzo[a]pyrene diol epoxide deoxyguanine adducts: implications for molecular interactions between integrase and substrates.
abstract: The viral protein HIV-1 integrase is required for insertion of the viral genome into human chromosomes and for viral replication. Integration proceeds in two consecutive integrase-mediated reactions: 3'-processing and strand transfer. To investigate the DNA minor groove interactions of integrase relative to known sites of integrase action, we synthesized oligodeoxynucleotides containing single covalent adducts of known absolute configuration derived from trans-opening of benzo-[a]pyrene 7,8-diol 9,10-epoxide by the exocyclic 2-amino group of deoxyguanosine at specific positions in a duplex sequence corresponding to the terminus of the viral U5 DNA. Because the orientations of the hydrocarbon in the minor groove are known from NMR solution structures of duplex oligonucleotides containing these deoxyguanosine adducts, a detailed analysis of the relationship between the position of minor groove ligands and integrase interactions is possible. Adducts placed in the DNA minor groove two or three nucleotides from the 3'-processing site inhibited both 3'-processing and strand transfer. Inosine substitution showed that the guanine 2-amino group is required for efficient 3'-processing at one of these positions and for efficient strand transfer at the other. Mapping of the integration sites on both strands of the DNA substrates indicated that the adducts both inhibit strand transfer specifically at the minor groove bound sites and enhance integration at sites up to six nucleotides away from the adducts. These experiments demonstrate the importance of position-specific minor groove contacts for both the integrase-mediated 3'-processing and strand transfer reactions.
authors: Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, and Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA.
authors: Allison A
authors: AA
authors: Johnson
authors: Jane M
authors: JM
authors: Sayer
authors: Haruhiko
authors: H
authors: Yagi
authors: Govind P
authors: GP
authors: Kalena
authors: Ronak
authors: R
authors: Amin
authors: Donald M
authors: DM
authors: Jerina
authors: Yves
authors: Y
authors: Pommier
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004279:DNA, Viral / Q000737:chemistry; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D019427:HIV Integrase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D011994:Recombinant Proteins
chemical_list: D004279:DNA, Viral; D011994:Recombinant Proteins; C418058:benzo(a)pyrene 7,8-diol-9,10-epoxide-N2-deoxyguanosine; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D004247:DNA; D019427:HIV Integrase; D003849:Deoxyguanosine