3HEF

Crystal structure of the bacteriophage Sf6 terminase small subunit

Summary for 3HEF

• Entry DOI: 10.2210/pdb3hef/pdb
• Descriptor: Gene 1 protein (2 entities in total)
• Functional Keywords: bacteriophage sf6, terminase small subunit gp1, gp1 octameric assembly, gp1 channel, dna recognition, dna packaging, viral protein
• Biological source: Enterobacteria phage Sf6 (Shigella flexneri bacteriophage VI)
• Total number of polymer chains: 2
• Total formula weight: 31718.11

Authors

Zhao, H.,Tang, L. (deposition date: 2009-05-08, release date: 2010-02-09, Last modification date: 2024-02-21)

Primary citation

Zhao, H.,Finch, C.J.,Sequeira, R.D.,Johnson, B.A.,Johnson, J.E.,Casjens, S.R.,Tang, L.
Crystal structure of the DNA-recognition component of the bacterial virus Sf6 genome-packaging machine
Proc.Natl.Acad.Sci.USA, 107:1971-1976, 2010

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

PubMed: 20133842
DOI: 10.1073/pnas.0908569107

Experimental method

X-RAY DIFFRACTION (1.65 Å)