Structural and Biochemical Studies of Crenarchael Viral Proteins

Montana State University, Bozeman MT

Investigators

Abstract

Crenarchaeal viruses such as SSV and STIV exist in extreme thermal (175 to 200 degrees Fahrenheit) and acidic (1.0 < pH < 3.0) environments such as those found in Yellowstone National Park. While SSV and STIV are among the best characterized Crenarchaeal viruses, our understanding of these unique hyperthermophilic viruses is limited. For example, sequence analysis of the SSV and STIV genomes fails to identify homologues for the majority of the putative genes. Hence, most viral proteins have yet to be assigned any function, and the roles that these proteins play in the viral life cycles remains a mystery. This project uses structural biology and biochemistry to (i) investigate the functional roles of the SSV and STIV proteomes. The structures of these proteins will be determined using X-ray crystallography. In many cases, the similarity of a structure to those in the Protein Data Bank is expected to suggest a function for the viral protein. In addition, this project seeks to (ii) identify viral or host proteins, or DNA sequences, that interact with specific viral proteins to form higher order complexes. Identification of these interacting macromolecules will provide further functional insight. Together, these efforts will contribute to an increased understanding of the SSV and STIV life cycles at the molecular level and thus this project represents a significant step toward understanding the unique viruses that inhabit these extreme environments. In addition, these viruses are of great interest because they serve as model systems for understanding the biochemistry and molecular biology required for life at high temperatures. Through their interactions with host machinery, they provide entry points for the study of important biochemical events, thus opening windows onto the most fundamental processes of the still poorly understood Crenarchaeota. Historically, viruses have also been a source of novel enzymes for biotechnology, particularly enzymes involved in nucleic acid biosynthesis and modification. Thus, identification of thermostable enzymes from the Crenarchaeal viruses might have important applications in biotechnology. Finally, the insights to be gained from comparative investigation of viruses from all three domains of life will be helpful in providing a better understanding of viral genesis and evolution. Broader Impacts: Much of the ongoing work within the Thermal Biology Institute (TBI) at Montana State University is being communicated to the general public by TBI outreach programs. Work on hyperthermophilic viruses is one of the focal points within TBI and is thus a major focus of these outreach efforts. Partners in outreach include the National Park Service /Yellowstone National Park, and involve preparation and review of materials for public presentation within the Park. The Park System is increasingly aware, as is the general public, of the unique microbial organisms inhabiting these world famous thermal features, and is working to increase the educational signage within the park that describes these organisms. There is strong integration of the research with the educational goals of the PI, the Department, the University, and the NSF. Students at the high school, undergraduate, doctoral and post-doctoral levels will receive significant training in biochemistry, structural biology and thermal biology. The participation of under represented groups, particularly women and Native Americans is encouraged, and their participation is well documented.