Life Sciences Seminar: Building on “déjà vu” to understand giant phage head assembly and function

Life Sciences Seminar
Building on “déjà vu” to understand giant phage head assembly and function

Dr. Julie Thomas
Associate Professor
Thomas H. Gosnell Scholl of Life Sciences, RIT

Abstract:
Phage research is undergoing a renaissance due to the abundance and diversity of phages in the environment, as well as their use to control multi-drug resistant bacteria. The virions of all tailed phages consist of a head and a tail. The head is an anciently-derived icosahedral structure that forms a thin outer shell to protect the genome. The tail functions to recognize an appropriate host and then initiates infection by delivering the genome into the cell. There is considerable structural and functional diversity between the virions of different phages. In this seminar, I will discuss our research on the large Salmonella phage SPN3US whose complex head has déjà vu-like similarities to that of the model E. coli phage T4. These similarities are subtle, easily obscured by the major structural differences between the two phages, and derive from the conservation of several proteins that drive major steps in head morphogenesis. One of those steps involves the proteolytic maturation of precursor head particles (proheads) that allows them to then undergo genome packaging. Proteolytic maturation is one of the most poorly understood steps in head assembly, yet it is essential. Our goal is to define the molecular cues that control proteolytic maturation in T4 and SPN3US so they can be exploited to package non-phage proteins into their heads.

Speaker Bio:
Dr. Julie Thomas is a molecular geneticist whose research focuses on viruses that infect bacteria (phages). She obtained her Ph.D. from La Trobe University Australia (Biotechnology) and undertook postdoctoral fellowships at the University of Texas Health Science Center San Antonio and the University of Maryland School of Medicine before joining GSoLSs in 2014. Her research utilizes multiple approaches to understand the replication mechanisms of large, so-called giant phages. Several of these phages are laboratory “stars” in her courses Phage Biology, and Molecular and Viral Genetics.

Intended Audience:
Beginners, undergraduates, graduates. Those with interest in the topic.

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