Bypassing BamD essentiality by mutations in a non-essential substrate.

ABSTRACT: The β-barrel assembly machinery (Bam) is essential for assembling all transmembrane β-barrel outer membrane proteins in gram-negative bacteria. The Bam complex consists of the central β-barrel protein BamA and accessory Bam lipoproteins, including the widely conserved and essential BamD. BamD is assumed to be an essential regulator of OMP assembly, as its absence causes a global defect in OMP biogenesis. Here, we challenge this view by demonstrating that BamD essentiality is both conditional and substrate specific. In Escherichia coli, its function can be bypassed by preventing BamA jamming by a single, non-essential substrate RcsF. Our findings suggest that BamD plays two distinct roles in the Bam complex. It prevents improper RcsF engagement that can jam BamA, and it kinetically e

SUBMITTER: Kumar S 

PROVIDER: S-EPMC12421809 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature