Crystal structure of the DNA-recognition component of the bacterial virus Sf6 genome-packaging machine

• DOI: 10.1073/pnas.0908569107
• Publication Date: 2010-01-20T04:53:28Z
• Authors: Haiyan Zhao; Casey J. Finch; Reuben D. Sequeira; Brian A. Johnson; John E. Johnson; Sherwood R. Casjens; Liang Tang
• Keywords: Histone octamer; Molecular machine; Viral protein; Concatemer

In herpesviruses and many bacterial viruses, genome-packaging is a precisely mediated process fulfilled by virally encoded molecular machine called terminase that consists of two protein components: A DNA-recognition component defines the specificity for packaged DNA, catalytic provides energy packaging reaction hydrolyzing ATP. The docks onto portal complex embedded in single vertex preformed viral shell procapsid, pumps DNA into procapsid through conduit formed portal. Here we report 1.65 resolution structure gp1 Shigella bacteriophage Sf6 machine. reveals ring-like octamer interweaved monomers with highly extended fold, embracing tunnel which may be translocated. N-terminal DNA-binding domains form peripheral appendages surrounding octamer. central domain contributes to oligomerization interactions bundled helices. C-terminal forms barrel parallel beta-strands. common scheme components, insights role formation packaging-competent assembly portal, oligomers stack together continuous channel translocation.