The structural basis of interspecies bacterial quorum sensing

ITQB Seminar

 

Title:  "The structural basis of interspecies bacterial quorum sensing"

Speaker: Stephen T. Miller

Affiliation: Department of Chemistry and Biochemistry, Swarthmore College

http://www.swarthmore.edu/NatSci/smiller1/Miller_Lab/Stephen_Miller.html

Host: Karina Xavier Head of  Bacterial Signalling Laboratory

 Abstract

Bacteria communicate through a process termed quorum sensing in which small chemical signals are produced, released into the environment, and detected by other bacteria.  Bacteria modulate gene expression in response to these signals, and thus are able to regulate behaviors such as virulence, motility, and biofilm formation in a population-wide manner.  While most autoinducers mediate communication within a bacterial species, a novel signal molecule, autoinducer-2 (AI-2), facilitates interspecies signaling. We have shown that different species of bacteria recognize chemically distinct, but interconvertable, forms of AI-2.  Since knowledge of the chemical identity of AI-2 recognized by a particular species is essential for the design of molecules that exploit quorum sensing to influence bacterial behavior, we have used bioinformatics and biochemical methods to identify and characterize AI-2 receptors from a range of bacterial species.  We are also using structural and biochemical methods to study the AI-2 processing proteins LsrF and LsrG and thus determine the ultimate cellular fate of AI-2.