The structure of a thermophilic archaeal virus shows a double-stranded DNA viral capsid type that spans all domains of life
- George Rice*,†,
- Liang Tang‡,
- Kenneth Stedman§,
- Francisco Roberto¶,
- Josh Spuhler*,†,
- Eric Gillitzer∥,
- John E. Johnson‡,
- Trevor Douglas*,†,**, and
- Mark Young*,†,∥,††
- *Thermal Biology Institute and Departments of †Microbiology, **Chemistry and Biochemistry, and ∥Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717; ‡Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037; §Biology Department, Portland State University, Portland, OR 97207; and ¶Biotechnology Department, Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID 83415
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Communicated by George Bruening, University of California, Davis, CA, March 12, 2004 (received for review December 2, 2003)
Abstract
Of the three domains of life (Eukarya, Bacteria, and Archaea), the least understood is Archaea and its associated viruses. Many Archaea are extremophiles, with species that are capable of growth at some of the highest temperatures and extremes of pH of all known organisms. Phylogenetic rRNA-encoding DNA analysis places many of the hyperthermophilic Archaea (species with an optimum growth ≳80°C) at the base of the universal tree of life, suggesting that thermophiles were among the first forms of life on earth. Very few viruses have been identified from Archaea as compared to Bacteria and Eukarya. We report here the structure of a hyperthermophilic virus isolated from an archaeal host found in hot springs in Yellowstone National Park. The sequence of the circular double-stranded DNA viral genome shows that it shares little similarity to other known genes in viruses or other organisms. By comparing the tertiary and quaternary structures of the coat protein of this virus with those of a bacterial and an animal virus, we find conformational relationships among all three, suggesting that some viruses may have a common ancestor that precedes the division into three domains of life >3 billion years ago.
Footnotes
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↵ †† To whom correspondence should be addressed. E-mail: myoung{at}montana.edu.
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Abbreviations: dsDNA, double-stranded DNA; YNP, Yellowstone National Park; TEM, transmission electron microscope; MALDI, matrix-assisted laser desorption ionization; STIV, Sulfolobus turreted icosahedral virus.
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Data deposition: The sequence reported in this paper has been deposited in the GenBank database (accession no. AY569307).
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See Commentary on page 7495.
- Copyright © 2004, The National Academy of Sciences
