First Advisor

Dr. Kenneth Stedman

Date of Award

Spring 6-7-2024

Document Type


Degree Name

Bachelor of Science (B.S.) in Biology and University Honors






virology, extremophile, mutagenesis, SSV1, nanogold, archaea


The tail of Saccharolobus spindle-shaped virus 1 (SSV1) has long been thought to be composed solely of viral protein 4 (VP4), but recent SSV1 structural studies have implicated the presence of additional structural proteins C166 and B78 in SSV1’s unique tail. The exact locations of these proteins have not been confirmed. Structural proteins VP4 (C-terminus) and B78 are hypothesized to contribute to an adapter region bridging the viral capsid to the tail, whereas C166 is thought to comprise the majority of an internal extended structure, respectively. SSV1 structural proteins lack cysteine residues providing targets to determine their locations in the virion. Mutations were made in the open reading frames of these proteins via site-directed mutagenesis in order to introduce cysteine residues at regions of interest in C166 and B78 selected using AlphaFold predictions. These residues allow conjugation of cysteine-specific gold nanoparticles at these sites, thus allowing precise localization of the proteins on the SSV1 virion. Five mutants were designed, two of which were introduced in E. coli plasmids, but all have yet to infect its natural host, S. solfataricus, a necessary step for transmission electron microscope imaging. Results of this project will elicit a better understanding of how these proteins are present in SSV1’s tail structure and contribute to the astonishing thermoacidophilic stability of SSV1.

Included in

Virology Commons