Heterosexual transmission of HIV-1 is widespread in Southern Africa. Heteroduplex mobility assays (HMA) and phylogenetic analyses of V3-V5 envelope (env) gene sequences demonstrate that subtype C predominates in Zimbabwe. To elucidate factors contributing to the epidemic in Zimbabwe, clinical and virologic characteristics of recently acquired subtype C HIV-1 infection among 21 men and 1 woman were determined. In 12 of 19 men providing clinical histories, a sexually transmitted infection preceded serologic evidence of HIV-1, and 14 of 19 men complained of rash or fever before seroconversion. Quantitative p24 antigen levels, reverse transcriptase activity, and HIV RNA levels of 22 viral isolates correlated with in vitro infectivity in peripheral blood mononuclear cells (p < .05). Biologic phenotype assessed in MT-2 cells demonstrated that 3 of 22 isolates (14%) were syncytia inducing (SI) and the remaining 19 nonsyncytium inducing (NSI). Early growth of virus in culture was associated with increased plasma HIV RNA levels, decreased CD4 cell levels, and SI virus. Recent subtype C HIV-1 infection through heterosexual transmission in Zimbabwe demonstrated clinical and virologic features consistent with reports of seroconversion to subtype B viruses.

helix DNA-binding proteins, including the C-tetminal domain of procaryotic catabolite gene activator protein (CAP), the globular domain of the linker histone HS, and the DNA-binding domain of the hepatocyte nuclear factor-3 (HNF-3). By aligning the helixturn-helix motif of Mbpl with that of CAP and HNF-3, we can suggest the following protein DNA interactions for the Mbpl-DNA complex: major groove contacs with DNA by the recognition helix within the helix-him-helix motif, as well as minor groove contacts by the loop of the ~-hairpin. ~ PS04.05.35 CRYSTALLIZATION OF THE FELINE lJ.vl-MUNODEFICIENCY VIRUS INTEG RASE PROTEIN.