Reconstituting Spore Cortex Peptidoglycan Biosynthesis Reveals a Deacetylase That Catalyzes Transamidation.

Some bacteria survive in nutrient-poor environments and resist killing by antimicrobials by forming spores. The cortex layer of the peptidoglycan cell wall that surrounds mature spores contains a unique modification, muramic-δ-lactam, that is essential for spore germination and outgrowth. Two proteins, the amidase CwlD and the deacetylase PdaA, are required for muramic-δ-lactam synthesis in cells, but their combined ability to generate muramic-δ-lactam has not been directly demonstrated.