The viral authors of evolution from sequence to structure

Abstract

Viruses are the most abundant biological entities on the planet. Like any parasite, these genetic parasites require a host. Inside a host cell, viruses hijack the transcription and translation machinery to replicate. In response to the ubiquitous threat of viral predation, host cells have evolved an astonishing diversity of mechanisms to stop, control, and even repurpose pieces of viruses. In this dissertation, I use bioinformatic, biochemical, and structural approaches to show this ancient conflict shapes host evolution by constantly rewriting the host genome. Research conducted during this dissertation has spanned the domains of life with three major foci. First, I have used bioinformatics to identify genetic parasites and defense systems embedded within algal and human genomes. Second, I have conducted deep evolutionary analyses to identify viral genes that have been repurposed for host function. And third, I have used cryogenic electron microscopy to determine the structure of viral defense systems in bacteria.