An N-Terminal Retention Module Anchors the Giant Adhesin LapA of Pseudomonas fluorescens at the Cell Surface: a Novel Subfamily of Type I Secretion Systems.

ABSTRACT: LapA of Pseudomonas fluorescens Pf0-1 belongs to a diverse family of cell surface-associated bacterial adhesins that are secreted via the type I secretion system (T1SS). We previously reported that the periplasmic protease LapG cleaves the N terminus of LapA at a canonical dialanine motif to release the adhesin from the cell surface under conditions unfavorable to biofilm formation, thus decreasing biofilm formation. Here, we characterize LapA as the first type I secreted substrate that does not follow the "one-step" rule of T1SS. Rather, a novel N-terminal element, called the retention module (RM), localizes LapA at the cell surface as a secretion intermediate. Our genetic, biochemical, and molecular modeling analyses support a model wherein LapA is tethered to the cell surface thr

SUBMITTER: Smith TJ 

PROVIDER: S-EPMC5869472 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature