title: Small-angle X-ray characterization of the nucleoprotein complexes resulting from DNA-induced oligomerization of HIV-1 integrase.
abstract: HIV-1 integrase (IN) catalyses integration of a DNA copy of the viral genome into the host genome. Specific interactions between retroviral IN and long terminal repeats (LTR) are required for this insertion. To characterize quantitatively the influence of the determinants of DNA substrate specificity on the oligomerization status of IN, we used the small-angle X-ray scattering (SAXS) technique. Under certain conditions in the absence of ODNs IN existed only as monomers. IN preincubation with specific ODNs led mainly to formation of dimers, the relative amount of which correlated well with the increase in the enzyme activity in the 3'-processing reaction. Under these conditions, tetramers were scarce. Non-specific ODNs stimulated formation of catalytically inactive dimers and tetramers. Complexes of monomeric, dimeric and tetrameric forms of IN with specific and non-specific ODNs had varying radii of gyration (R(g)), suggesting that the specific sequence-dependent formation of IN tetramers can probably occur by dimerization of two dimers of different structure. From our data we can conclude that the DNA-induced oligomerization of HIV-1 IN is probably of importance to provide substrate specificity and to increase the enzyme activity.
authors.affiliation: Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences, Lavrentieva Ave. 8, 630090, Russia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Baranova
authors.forename: Fedor V
authors.initials: FV
authors.lastname: Tuzikov
authors.forename: Olga D
authors.initials: OD
authors.lastname: Zakharova
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Tuzikova
authors.forename: Christina
authors.initials: C
authors.lastname: Calmels
authors.forename: Simon
authors.initials: S
authors.lastname: Litvak
authors.forename: Laura
authors.initials: L
authors.lastname: Tarrago-Litvak
authors.forename: Vincent
authors.initials: V
authors.lastname: Parissi
authors.forename: Georgy A
authors.initials: GA
authors.lastname: Nevinsky
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D019427:HIV Integrase / Q000737:chemistry* / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology*; D007700:Kinetics; D009698:Nucleoproteins / Q000737:chemistry* / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D053838:Scattering, Small Angle; D013379:Substrate Specificity; D014961:X-Ray Diffraction
chemical_list: D009698:Nucleoproteins; D009838:Oligodeoxyribonucleotides; D004247:DNA; D019427:HIV Integrase