A conserved signal-peptidase antagonist modulates membrane homeostasis of actinobacterial sortase critical for surface morphogenesis.

ABSTRACT: Most Actinobacteria encode a small transmembrane protein, whose gene lies immediately downstream of the housekeeping sortase coding for a transpeptidase that anchors many extracellular proteins to the Gram-positive bacterial cell wall. Here, we uncover the hitherto unknown function of this class of conserved proteins, which we name SafA, as a topological modulator of sortase in the oral Actinobacterium Actinomyces oris. Genetic deletion of safA induces cleavage and excretion of the otherwise predominantly membrane-bound SrtA in wild-type cells. Strikingly, the safA mutant, although viable, exhibits severe abnormalities in cell morphology, pilus assembly, surface protein localization, and polymicrobial interactions-the phenotypes that are mirrored by srtA depleti

SUBMITTER: Ramirez NA 

PROVIDER: S-EPMC9282373 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature