Department of Biochemistry and Molecular Pharmacology
Amino Acids, Peptides, and Proteins | Biochemistry | Enzymes and Coenzymes | Genetic Phenomena | Nucleic Acids, Nucleotides, and Nucleosides | Structural Biology | Viruses
Virus capsid proteins reproducibly self-assemble into regularly-shaped, stable shells that protect the viral genome from external environmental assaults, while maintaining the high internal pressure of the tightly packaged viral genome. To elucidate how capsids maintain stability under harsh conditions, we investigated the capsid components of a hyperthermophilic virus, phage P74-26. We determined the structure of a capsid protein gp87 and show that it has the same fold as trimeric decoration proteins that enhance the structural stability of capsids in many other phage, despite lacking significant sequence homology. We also find that gp87 is significantly more stable than its mesophilic homologs, reflecting the high temperature environment in which phage P74-26 thrives. Our analysis of the gp87 structure reveals that the core domain of the decoration protein is conserved in trimeric capsid components across numerous dsDNA viruses, including human pathogens such as Herpesviruses. Moreover, this core β-barrel domain is found in the anti-CRISPR protein AcrIIC1, which suggests a mechanism for the evolution of this broad spectrum Cas9 inhibitor. Our work illustrates the principles for increased stability of a thermophilic decoration protein, and extends the evolutionary reach of the core trimeric decoration protein fold.
biochemistry, hyperthermophilic phage decoration protein, evolution, herpesvirus
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The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It is made available under a CC-BY-NC-ND 4.0 International license.
DOI of Published Version
bioRxiv 216911; doi: https://doi.org/10.1101/216911. Link to preprint on bioRxiv service.
Stone NP, Hilbert BJ, Hidalgo D, Halloran KT, Kelch BA. (2017). A hyperthermophilic phage decoration protein suggests common evolutionary origin with Herpesvirus Triplex proteins and an anti-CRISPR protein. University of Massachusetts Medical School Faculty Publications. https://doi.org/10.1101/216911. Retrieved from https://escholarship.umassmed.edu/faculty_pubs/1545
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This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
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