Figure 1. Phage-inducible chromosomal island-like element (PLE) encodes an inhibitory protein, TcaP, which modifies ICP1’s capsid assembly process to produce small capsids.
(A, B) Representative transmission electron micrographs (TEMs) from three independent biological replicates show (A) PLE virions have small, ~50-nm-wide capsids and long contractile tails while. (B) ICP1 virions have large, ~80-nm-wide capsids and long contractile tails. Scale bars are 200 nm. (C, D) Representative TEMs of lysates produced from ICP1 infection of V. cholerae expressing (C) TcaP (ptcaP) or (D) an empty vector (pEV). Arrowheads show exemplary capsids and their sizes according to the legend. Scale bars are 200 nm. (E) Efficiency of plaquing of wild type ICP1 or escape phages harboring the substitution indicated in the coat protein on V. cholerae expressing TcaP relative to an empty vector control. Each dot represents a biological replicate, bars represent the mean, and error bars show the standard deviation. The dotted line indicates an efficiency of plaquing of 1 where the expression of TcaP is not inhibitory to plaque formation.

