Skip to main content

Elucidating the molecular mechanisms of Vibrio cholerae toxin coregulated pilus assembly, bundling and CTXф interactions

Resource type
Thesis type
(Thesis) M.Sc.
Date created
Vibrio cholerae use toxin-coregulated pili (TCP) to colonize the human intestine and cause severe diarrheal disease, cholera. TCP are surface filaments that self-aggregate to hold the bacteria in microcolonies that protect them from host defences and provide concentrated amounts of secreted cholera toxin. Also, TCP are receptors for a filamentous bacteriophage, CTXф, which carries the cholera toxin genes. To understand TCP assembly, TCP-mediated microcolony formation, and TCP:CTXф interactions at the molecular level, structure-based mutagenesis and functional assays were employed. I show charge complementarity between pilin subunits is important for initiating TCP assembly and hydrophobic interactions between subunits are required for pilus stability. I propose a model for pilus interactions whereby protruding regions of the TCP intercalate into depressions in adjacent TCP to form specific interactions that hold cells in microcolonies. Mutagenesis, immuno-gold electron microscopy analysis and functional assays suggest that CTXф attachment occurs over a large surface of TCP.
Copyright statement
Copyright is held by the author.
Scholarly level
Download file Size
etd4418.pdf 6.65 MB

Views & downloads - as of June 2023

Views: 0
Downloads: 0