CotL, a new morphogenetic spore coat protein of Clostridium difficile

Abstract

Summary The strict anaerobe Clostridium difficile is the most common cause of antibiotic‐associated diarrhoea. The oxygen‐resistant C. difficile spores play a central role in the infectious cycle, contributing to transmission, infection and recurrence. The spore surface layers, the coat and exosporium, enable the spores to resist physical and chemical stress. However, little is known about the mechanisms of their assembly. In this study, we characterized a new spore protein, CotL, which is required for the assembly of the spore coat. The cotL gene was expressed in the mother cell compartment under the dual control of the RNA polymerase sigma factors, σE and σK. CotL was localized in the spore coat, and the spores of the cotL mutant had a major morphologic defect at the level of the coat/exosporium layers. Therefore, the mutant spores contained a reduced amount of several coat/exosporium proteins and a defect in their localization in sporulating cells. Finally, cotL mutant spores were more sensitive to lysozyme and were impaired in germination, a phenotype likely to be associated with the structurally altered coat. Collectively, these results strongly suggest that CotL is a morphogenetic protein essential for the assembly of the spore coat in C. difficile.

From Root to Tips: Sporulation Evolution and Specialization inBacillus subtilisand the Intestinal PathogenClostridioides difficile

“…4B). Also, CotL (Entrez GI:126698652), important for the assembly of the coat/exosporium (Alves Feliciano et al. 2019) appeared in branch 11, at base of the Clostridioides.…”

Structural, Metabolic and Evolutionary Comparison of Bacterial Endospore and Exospore Formation

“…The endospore coat is a multilayer protein structure that encapsulates the OsM and provides protection from lytic enzymes, heat, physical disruption, UV radiation, predation and other factors ( Figures 2G,H) (Riesenman and Nicholson, 2000;Klobutcher et al, 2006;Setlow, 2006;Alves Feliciano et al, 2019). The coat is a highly complex structure made up of dozens of proteins, many of which are unique to individual species.…”

“…Additional spore coat morphogenesis proteins of Bacilli include SafA and CotE, which are essential for formation of the inner and outer coat layers, respectively (Zheng et al, 1988;Takamatsu et al, 1999;Abhyankar et al, 2013;Stelder et al, 2018). In Clostridia, a recently identified protein, CotL, has been deemed important for assembly of the coat, although its function is poorly understood (Alves Feliciano et al, 2019). Altogether, the endospore coat usually comprises multiple layers, each characterized by distinct morphogenic and structural proteins (McKenney et al, 2010;Stelder et al, 2018).…”

Identification of a novel regulator ofClostridioides difficilecortex formation

“…Finally, the coat layers of ∆ spoVQ spores were similar in thickness and appearance to wild-type spores, suggesting that loss of SpoVQ specifically affects cortex thickness (Figure 3C). Interestingly, the thinner cortex of ∆ spoVQ spores resembled that of cotL mutant spores (26). Like SpoVQ, CotL is a mother cell-specific, σ E -regulated protein found exclusively in the Peptostreptococcaceae family that affects cortex thickness (26).…”

“…A C. difficile sipL mutant resembles a C. difficile spoIVA mutant in that both fail to polymerize coat layers around the forespore and produce cortex layers that are often irregular in shape and thickness (18,20,25). CotL is a Peptostreptococcaceae family-specific coat morphogenetic protein that also regulates cortex thickness (26). Loss of CotL strongly impairs the localization and/or retention of coat and cortex-localized proteins in mature spores, which also produce a thinner cortex layer.…”