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Cryo-EM characterization of functional components of a Bacteriophage exclusion system


EMSL Project ID
51341

Abstract

The strategies employed by bacteria and archaea for combatting phage infection, and the corresponding ‘arms race’ between phage and their microbial targets, have generated a diverse arsenal of innate and adaptive systems for cellular defense and an equally broad collection of phage resistance mechanisms. A poorly understood phage restriction mechanism, named Bacteriophage Exclusion (‘BREX’), is widely distributed throughout bacteria that inhibit phage replication. The mechanisms by which BREX systems operate are entirely unknown.

We have recently produced and purified recombinant proteins corresponding to each component of a typical BREX system. Preliminary cryo-EM analysis revealed that BrxL, a potential homologue of Lon protease, forms a heptameric cylinder similar to archaea and eukaryal proteasomes. We propose to characterize, by cryo-EM and X-ray crystallography, the structure of BrxL in the presence and absence of ATP, as a first step toward the elucidation of the role of BrxL in phage resistance.

Project Details

Start Date
2020-05-15
End Date
2020-08-15
Status
Closed

Team

Principal Investigator

Betty Shen
Institution
Fred Hutchinson Cancer Research Center

Team Members

Barry Stoddard
Institution
Fred Hutchinson Cancer Research Center