FlgJ cell-wall hydrolyzing activity enhances, but is not required, for flagellum assembly in Salmonella enterica.

Salmonella enterica can assemble functional flagella without FlgJ’s cell-wall hydrolyzing activity, though at reduced efficiency, demonstrating diverse flagellar assembly mechanisms.

• Why it matters: Understanding how bacteria penetrate the peptidoglycan layer during flagellum assembly is crucial for insights into bacterial motility and pathogenicity, especially given the assumed necessity of cell wall degradation.
• What they did: Researchers tested FlgJ catalytic mutants and manipulated gene expression, including deleting flgM, to assess flagellar assembly and the role of FlgJ’s enzymatic activity in Salmonella.
• The result: Findings show that flagellar assembly persists without FlgJ’s hydrolyzing function, with increased gene expression partially compensating, highlighting evolutionary diversity in bacterial flagellum formation strategies.