(Montana State University - Bozeman, College of Letters & Science, 2006) Larson, Eric Thomas; Chairperson, Graduate Committee: C. Martin Lawrence
Sulfolobus turreted icosahedral virus (STIV) was isolated from acidic hot springs of Yellowstone National Park and was the first hyperthermophilic virus described with icosahedral capsid architecture. Structural analysis of the STIV particle and its major capsid protein suggests that it belongs to a lineage of viruses that predates the division of the three domains of life. Functional predictions of the viral proteins are hindered because they lack similarity to sequences of known function. Protein structure, however, may suggest functional relationships that are not apparent from the sequence. Thus, we have initiated crystallographic studies of STIV and expect to gain functional insight into its proteins while illuminating the viral life cycle. These studies may also provide genetic, biochemical, and evolutionary insight into its thermoacidophilic host and the requirements for life in these harsh environments. The first three proteins studied in structural detail are A197, B116, and F93. As anticipated, these structures suggest possible functions. The structure of A197 reveals a glycosyltransferase GT-A fold.
