Crippling the bacterial cell wall molecular machinery

Abstract

Lytic transglycosylases (LT) are redundant enzymes that play a critical role in peptidoglycan (PG) recycling and metabolism. LT(s) role in cell wall-modifying complexes and usefulness as antimicrobial drug targets remain elusive. We determined at high-resolution a structure of the membrane-bound homolog of the soluble LT from Neisseria species with a disordered active site helix (alpha helix 30). Alpha helix 30 is crucial for binding PG during catalysis1. Here we show using an alpha helix 30 deletion strain that LT (LtgA) determines the integrity of the cell wall, participates in cell division and separation, and can be manipulated to impair the fitness of the human pathogen Neisseria meningitidis during infection. Characterization of ltgA helix deleted strain interactome identified glycan chain remodeling enzymes whose function appear to be modulated by LTs. Targeting LTs can disrupt the PG machinery, which is fatal for the bacterium, a new approach for antibiotic development.