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bioRxiv · 10.1101/2023.10.06.561273

Bacterial cell surface nanoenvironment requires a specialized chaperone to activate a peptidoglycan biosynthetic enzyme

Delerue, T.·Chareyre, S.·Anantharaman, V.·Gilmore, M. C.·Popham, D. L.·Cava, f.·Aravind, L.·Ramamurthi, K. S.
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Abstract

Bacillus subtilis spores are produced inside the cytosol of a mother cell. Spore surface assembly requires the SpoVK protein in the mother cell, but its function is unknown. Here, we report that SpoVK is a dedicated chaperone from a distinct higher-order clade of AAA+ ATPases that activates the peptidoglycan glycosyltransferase MurG during sporulation, even though MurG does not normally require activation by a chaperone during vegetative growth. MurG redeploys to the spore surface during sporulation, where we show that the local pH is reduced and propose that this change in cytosolic nanoenvironment necessitates a specific chaperone for proper MurG function. Further, we show that SpoVK participates in a developmental checkpoint in which improper spore surface assembly inactivates SpoVK, which leads to sporulation arrest. The AAA+ ATPase clade containing SpoVK includes other dedicated chaperones involved in secretion, cell-envelope biosynthesis, and carbohydrate metabolism, suggesting that such fine-tuning might be a widespread feature of different subcellular nanoenvironments.

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Delerue, T., Chareyre, S., Anantharaman, V., Gilmore, M. C., Popham, D. L., Cava, f., Aravind, L., Ramamurthi, K. S.. 2023-10-06. Bacterial cell surface nanoenvironment requires a specialized chaperone to activate a peptidoglycan biosynthetic enzyme. https://doi.org/10.1101/2023.10.06.561273

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