Title: Coordinated Assembly of the Bacillus anthracis Coat and Exosporium during Bacterial Spore Outer Layer Formation

Journal Article · · mBio (Online)
 [1];  [1];  [1];  [2];  [1];  [1];  [3];  [3];  [3];  [2];  [1];  [4];  [5]
  1. Loyola Univ. Chicago, Maywood, IL (United States). Dept. of Microbiology and Immunology
  2. Univ. of Missouri, Columbia, MO (United States). Dept. of Veterinary Pathobiology and Bond Life Sciences Center
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Biosciences and Biotechnology Div.
  4. Univ. of Texas Houston, Houston, TX (United States)
  5. Harvard Univ., Cambridge, MA (United States)
+ Show Author Affiliations

Bacterial spores produced by the Bacillales are composed of concentric shells, each of which contributes to spore function. Spores from all species possess a cortex and coat, but spores from many species possess additional outer layers. The outermost layer of Bacillus anthracis spores, the exosporium, is separated from the coat by a gap known as the interspace. Exosporium and interspace assembly remains largely mysterious. As a result, we have a poor understanding of the overarching mechanisms driving the assembly of one of the most ubiquitous cell types in nature. To elucidate the mechanisms directing exosporium assembly, we generated strains bearing mutations in candidate exosporium-controlling genes and analyzed the effect on exosporium formation. Biochemical and cell biological analyses argue that CotE directs the assembly of CotO into the spore and that CotO might be located at or close to the interior side of the cap. Taken together with data showing that CotE and CotO interact directly in vitro, we propose a model in which CotE and CotO are important components of a protein interaction network that connects the exosporium to the forespore during cap formation and exosporium elongation. Our data also suggest that the cap interferes with coat assembly at one pole of the spore, altering the pattern of coat deposition compared to the model organism Bacillus subtilis. We propose that the difference in coat assembly patterns between these two species is due to an inherent flexibility in coat assembly, which may facilitate the evolution of spore outer layer complexity.

Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC52-07NA27344
OSTI ID:
1560106
Report Number(s):
LLNL-JRNL-774758; 967108
Journal Information:
mBio (Online), Journal Name: mBio (Online) Journal Issue: 6 Vol. 9; ISSN 2150-7511
Publisher:
American Society for MicrobiologyCopyright Statement
Country of Publication:
United States
Language:
English

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Expansion of the Spore Surface Polysaccharide Layer in Bacillus subtilis by Deletion of Genes Encoding Glycosyltransferases and Glucose Modification Enzymes journal June 2019

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