SecY-mediated quality control prevents the translocation of non-gated porins.

ABSTRACT: OmpC and OmpF are among the most abundant outer membrane proteins in E. coli and serve as hydrophilic channels to mediate uptake of small molecules including antibiotics. Influx selectivity is controlled by the so-called constriction zone or eyelet of the channel. Mutations in the loop domain forming the eyelet can disrupt transport selectivity and thereby interfere with bacterial viability. In this study we show that a highly conserved motif of five negatively charged amino acids in the eyelet, which is critical to regulate pore selectivity, is also required for SecY-mediated transport of OmpC and OmpF into the periplasm. Variants with a deleted or mutated motif were expressed in the cytosol and translocation was initiated. However, after signal peptide cleavage, import into the periplasm

SUBMITTER: Jung S 

PROVIDER: S-EPMC7530735 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature