1. A Clostridioides difficile endolysin modulates toxin secretion without cell lysis.
- Author
-
Awad, Milena M., Suraweera, Chathura D., Vidor, Callum J., Ye-Lin, Auberon Y., Williams, Galain C., Mileto, Steven J., Barlow, Christopher K., McGowan, Sheena, and Lyras, Dena
- Subjects
CLOSTRIDIOIDES difficile ,LYSIS ,AMIDASES ,PEPTIDOGLYCAN hydrolase ,TOXINS ,SECRETION - Abstract
The Clostridia produce and secrete Large Clostridial Glucosylating Toxins (LCGTs) responsible for disease symptoms, but the secretion mechanism is largely unknown. Recently, a holin-like protein was shown to be essential for toxin secretion. Holins, typically bacteriophage-specific proteins, are part of the holin-endo(lysin) system that releases phage progeny. To determine if the clostridia also use a lysin, we investigated two conserved putative lysins, M7404_01910 and M7404_02200, in the release of the LCGTs TcdA and TcdB from a Clostridioides difficile ribotype 027 strain, M7404. Sequence analysis and structural modelling indicates that both proteins are related to N-acetylmuramoyl-l-alanine amidases, similar to CD27L, a lysin from the C. difficile phage ΦCD27. Disruption of these genes reveal that only M7404_02200 contributes to toxin secretion and does so in a non-lytic fashion. Peptidoglycan hydrolysis assays show that recombinant M7404_02200 is an active peptidoglycan amidase, confirming its role in TcdA and TcdB secretion in C. difficile M7404. Identification of an N-acetylmuramoyl-l-alanine amidase in the ribotype 027 C. difficile strain M7404, involved in the active secretion of the large clostridial glucosylating toxins, TcdA and TcdB. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF