[Faculty] CSRC Colloquium: Phage capsid structure, this Friday at the BioScience Center

[Jose Castillo]

*DATE: * Friday, May 5th, 2017

*TITLE:*  Phage capsid structure: Theory, phage lifestyle constraints, and
environmental diagnostic

*TIME: * 3:30 PM

*LOCATION: * *Bioscience Center Gold Auditorium*

*SPEAKER:*   Dr. Antoni Luque, Dept. Math and Stats, CSRC, and Viral
Information Institute, SDSU

*ABSTRACT:  * Phages are viruses that infect bacteria and are the most
abundant entity on the planet. About eighty percent of these viruses are
made of a protein shell—the capsid—that stores the phage genome, adopts an
icosahedral shape, and has a tail that inoculates the genome into the
bacterial host. These phages have tuned this architecture to succeed in all
sorts of environments from the cold waters of the arctic and the hot
springs of Yellowstone to the mucosal surfaces of the human gut. We
hypothesize that the malleable and rapidly evolving structure of tailed
phages can be used as an early predictor of ecosystem changes due to
environmental factors. To address this, we developed a mathematical model
that predicts the structure of phages based on accessible environmental
data such as phage genome size or capsid size. We validated the theory for
30 phages that are well-characterized structurally, and we applied the
model to predict the structure associated to 500 phage genomes that have
been annotated with the bioinformatic platform PhAnToMe. The structural
analysis of these phages show that the lysogenic lifestyle—which allows
phages to integrate in the bacterial host—imposes a strong constraint on
the structure of the phage capsid. The lytic lifestyle—associated to the
predatory life cycle of phages—promotes instead structural variability of
the capsid. Despite the biological reason for this result remains unclear,
the methodology provides a new approach to study the emergence of lysogeny,
which has been linked to diseases and ecosystem degradation. To this end,
we have analyzed phage samples from the Curonian Lagoon (near the Baltic
sea), and we predict the emergence of lysogeny on the nearshore of
Klaipeda. This methodology has a broad range of potential applications, for
example, in the diagnosis of lysogenic variation within the human digestive
tract and respiratory tract.

*HOST:*  Dr. Jose Castillo


-- 

Jose E. Castillo  Ph.D.

Director / Professor

Computational Science Research Center

5500 Campanile Dr

San Diego State University

San Diego CA 92182-1245

619 5947205/3430, Fax 619-594-2459

 http://www.csrc.sdsu.edu/mimetic-book/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://engineering.sdsu.edu/pipermail/faculty/attachments/20170501/28126dd9/attachment.html>