The mechanism of DNA ejection in the Bacillus anthracis spore-binding phage 8a revealed by cryo-electron tomography
- Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States)
- Department of Biology, University of Northern Iowa, Cedar Falls, IA 50614 (United States)
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.
- OSTI ID:
- 22149247
- Journal Information:
- Virology, Vol. 421, Issue 2; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0042-6822
- Country of Publication:
- United States
- Language:
- English
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