GneZ, a UDP-GlcNAc 2-epimerase, is required for S-layer assembly and vegetative growth of Bacillus anthracis.

Abstract

Bacillus anthracis, the causative agent of anthrax, forms an S-layer atop its peptidoglycan envelope and displays S-layer proteins and Bacillus S-layer-associated (BSL) proteins with specific functions to support cell separation of vegetative bacilli and growth in infected mammalian hosts. S-layer and BSL proteins bind via the S-layer homology (SLH) domain to the pyruvylated secondary cell wall polysaccharide (SCWP) with the repeat structure [→4)-β-ManNAc-(1→4)-β-GlcNAc-(1→6)-α-GlcNAc-(1→]n, where α-GlcNAc and β-GlcNAc are substituted with two and one galactosyl residues, respectively. B. anthracis gneY (BAS5048) and gneZ (BAS5117) encode nearly identical UDP-GlcNAc 2-epimerase enzymes that catalyze the reversible conversion of UDP-GlcNAc and UDP-ManNAc. UDP-GlcNAc 2-epimerase enzymes have been shown to be required for the attachment of the phage lysin PlyG with the bacterial envelope and for bacterial growth. Here, we asked whether gneY and gneZ are required for the synthesis of the pyruvylated SCWP and for S-layer assembly. We show that gneZ, but not gneY, is required for B. anthracis vegetative growth, rod cell shape, S-layer assembly, and synthesis of pyruvylated SCWP. Nevertheless, inducible expression of gneY alleviated all the defects associated with the gneZ mutant. In contrast to vegetative growth, neither germination of B. anthracis spores nor the formation of spores in mother cells required UDP-GlcNAc 2-epimerase activity.

• Authors: Ya-Ting Wang, Dominique Missiakas, Olaf Schneewind
• Journal: Journal of bacteriology (J Bacteriol) Vol. 196 Issue 16 Pg. 2969-78 (Aug 15 2014) ISSN: 1098-5530 [Electronic] United States
• PMID: 24914184 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Chemical References

• Membrane Glycoproteins
• Polysaccharides, Bacterial
• S-layer proteins
• Carbohydrate Epimerases
• UDP acetylglucosamine-2-epimerase

Topics

• Bacillus anthracis (cytology, enzymology, genetics, growth & development)
• Carbohydrate Epimerases (genetics, metabolism)
• Gene Deletion
• Genetic Complementation Test
• Membrane Glycoproteins (metabolism)
• Polysaccharides, Bacterial (metabolism)
• Protein Multimerization