1. The unusual cell wall of the Lyme disease spirochaete Borrelia burgdorferi is shaped by a tick sugar.
- Author
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DeHart TG, Kushelman MR, Hildreth SB, Helm RF, and Jutras BL
- Subjects
- Animals, Borrelia burgdorferi genetics, Cell Wall chemistry, Cell Wall genetics, Host-Pathogen Interactions, Muramic Acids metabolism, Peptidoglycan metabolism, Sugars chemistry, Ticks metabolism, Borrelia burgdorferi metabolism, Cell Wall metabolism, Sugars metabolism, Ticks microbiology
- Abstract
Peptidoglycan-a mesh sac of glycans that are linked by peptides-is the main component of bacterial cell walls. Peptidoglycan provides structural strength, protects cells from osmotic pressure and contributes to shape. All bacterial glycans are repeating disaccharides of N-acetylglucosamine (GlcNAc) β-(1-4)-linked to N-acetylmuramic acid (MurNAc). Borrelia burgdorferi, the tick-borne Lyme disease pathogen, produces glycan chains in which MurNAc is occasionally replaced with an unknown sugar. Nuclear magnetic resonance, liquid chromatography-mass spectroscopy and genetic analyses show that B. burgdorferi produces glycans that contain GlcNAc-GlcNAc. This unusual disaccharide is chitobiose, a component of its chitinous tick vector. Mutant bacteria that are auxotrophic for chitobiose have altered morphology, reduced motility and cell envelope defects that probably result from producing peptidoglycan that is stiffer than that in wild-type bacteria. We propose that the peptidoglycan of B. burgdorferi probably evolved by adaptation to obligate parasitization of a tick vector, resulting in a biophysical cell-wall alteration to withstand the atypical torque associated with twisting motility., (© 2021. The Author(s).)
- Published
- 2021
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