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Male involvement in prevention of mother to child transmission of HIV (PMTCT) care improves maternal and child outcomes. We conducted a mixed-methods study at two Kenyan government hospitals. We quantitatively assessed women's expectations and preferences for male partner involvement in PMTCT and male partner attendance at PMTCT appointments. Qualitative interviews with women during the postpartum period assessed types of support women received from their male partners. At enrollment, most participants wanted (75%) and expected (69%) male partners to attend appointments; yet, only 9% had a male partner attend any appointments. Most women agreed that their partner would: support them financially (81%), help follow doctor's guidance (61%), support a hospital-based delivery (85%), and want to receive text messages (68%). Expectations and preferences varied by women's characteristics, most notably experiences with mistreatment, disclosure status, and knowledge of male partner's HIV status. In qualitative interviews, instrumental (financial) support was the most frequently discussed type of support. Male partners also provided informational support by reminding women of medication or appointments. Women reported a variety of ways in which their male partners supported them through PMTCT; however, there was a gap between women's expectation for male partner attendance and the level of male attendance achieved. [ABSTRACT FROM AUTHOR]

Many DNA viruses use powerful molecular motors to cleave concatemeric viral DNA into genome-length units and package them into preformed procapsid powered by ATP hydrolysis. Here we report the structures of the DNA-packaging motor gp2 of bacteriophage Sf6, which reveal a unique clade of RecA-like ATPase domain and an RNase H-like nuclease domain tethered by a regulatory linker domain, exhibiting a strikingly distinct domain arrangement. The gp2 structures complexed with nucleotides reveal, at the atomic detail, the catalytic center embraced by the ATPase domain and the linker domain. The gp2 nuclease activity is modulated by the ATPase domain and is stimulated by ATP. An extended DNA-binding surface is formed by the linker domain and the nuclease domain. These results suggest a unique mechanism for translation of chemical reaction into physical motion of DNA and provide insights into coordination of DNA translocation and cleavage in a viral DNA-packaging motor, which may be achieved via linker-domain-mediated interdomain communication driven by ATP hydrolysis. [ABSTRACT FROM AUTHOR]

Herpes simplex virus 1 (HSV-1), the prototypic member of herpesviruses, employs a virally encoded molecular machine called terminase to package the viral double-stranded DNA (dsDNA) genome into a preformed protein shell. The terminase contains a large subunit that is thought to cleave concatemeric viral DNA during the packaging initiation and completion of each packaging cycle and supply energy to the packaging process via ATP hydrolysis. We have determined the X-ray structure of the C-terminal domain of the terminase large-subunit pUL15 (pUL15C) from HSV-1. The structure shows a fold resembling those of bacteriophage terminases, RNase H, integrases, DNA polymerases, and topoisomerases, with an active site clustered with acidic residues. Docking analysis reveals a DNA-binding surface surrounded by flexible loops, indicating considerable conformational changes upon DNA binding. In vitro assay shows that pUL15C possesses non-sequence-specific, Mg2+-dependent nuclease activity. These results suggest that pUL15 uses an RNase H-like, metal ion-mediated catalysis mechanism for cleavage of viral concatemeric DNA. The structure reveals extra structural elements in addition to the RNase H-like fold core and variations in local architecture of the nuclease active site, which are conserved in herpesvirus terminases and bear great similarity to the phage T4 gpl7 but are distinct from podovirus and siphovirus orthologs and cellular RNase H, delineating a new evolutionary lineage among a large family of eukaryotic viruses and simple and complex prokaryotic viruses. [ABSTRACT FROM AUTHOR]