title: Biochemical analyses of the interactions between human immunodeficiency virus type 1 Vpr and p6(Gag).
abstract: The nonstructural human immunodeficiency virus type 1 Vpr protein is packaged into progeny virions at significant levels (approximately 200 copies/virion). Genetic analyses have demonstrated that efficient Vpr packaging is dependent upon a leucine-X-X-leucine-phenylalanine (LXXLF) motif located in the p6(Gag) domain of the structural Gag polyprotein. Recombinant proteins spanning full-length Vpr (Vpr(1-97)) or the amino-terminal 71 amino acids (Vpr(1-71)) formed specific complexes with recombinant p6 proteins in vitro. Complex formation required an intact LXXLF motif and exhibited an intrinsic dissociation constant of approximately 75 microM. Gel filtration and cross-linking analyses further revealed that Vpr(1-71) self-associated in solution. Our experiments demonstrate that Vpr can bind directly and specifically to p6 and suggest that oligomerization of both Vpr and Gag may serve to increase the avidity and longevity of Vpr-Gag complexes, thereby ensuring efficient Vpr packaging.
authors.affiliation: Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6148, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Jenkins
authors.forename: O
authors.initials: O
authors.lastname: Pornillos
authors.forename: R L
authors.initials: RL
authors.lastname: Rich
authors.forename: D G
authors.initials: DG
authors.lastname: Myszka
authors.forename: W I
authors.initials: WI
authors.lastname: Sundquist
authors.forename: M H
authors.initials: MH
authors.lastname: Malim
mesh_terms: D015374:Biosensing Techniques; D015683:Gene Products, gag / Q000737:chemistry* / Q000378:metabolism; D016336:Gene Products, vpr / Q000737:chemistry* / Q000378:metabolism; D015497:HIV-1 / Q000737:chemistry* / Q000502:physiology; D006801:Humans; D010446:Peptide Fragments / Q000737:chemistry; D011498:Protein Precursors / Q000737:chemistry* / Q000378:metabolism; D019065:Virus Assembly; D054325:vpr Gene Products, Human Immunodeficiency Virus
chemical_list: D015683:Gene Products, gag; D016336:Gene Products, vpr; D010446:Peptide Fragments; D011498:Protein Precursors; C059767:p55 gag precursor protein, Human immunodeficiency virus 1; D054325:vpr Gene Products, Human Immunodeficiency Virus