Faculty Publications

Title

The mechanism of DNA ejection in the Bacillus anthracis spore-binding phage 8a revealed by cryo-electron tomography

Document Type

Article

Keywords

Bacillus anthracis, Bacteriophage, Base plate, Contractile tail, Cryo-electron tomography, DNA ejection, Myoviridae, Phage infection, Tail contraction, Tail sheath

Journal/Book/Conference Title

Virology

Volume

421

Issue

2

First Page

141

Last Page

148

Abstract

The structure of the Bacillus anthracis spore-binding phage 8a was determined by cryo-electron tomography. The phage capsid forms a T = 16 icosahedron attached to a contractile tail via a head-tail connector protein. The tail consists of a six-start helical sheath surrounding a central tail tube, and a structurally novel baseplate at the distal end of the tail that recognizes and attaches to host cells. The parameters of the icosahedral capsid lattice and the helical tail sheath suggest protein folds for the capsid and tail-sheath proteins, respectively, and indicate evolutionary relationships to other dsDNA viruses. Analysis of 2518 intact phage particles show four distinct conformations that likely correspond to four sequential states of the DNA ejection process during infection. Comparison of the four observed conformations suggests a mechanism for DNA ejection, including the molecular basis underlying coordination of tail sheath contraction and genome release from the capsid. © 2011 Elsevier Inc.

Original Publication Date

12-20-2011

DOI of published version

10.1016/j.virol.2011.08.028

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