An unusual signal peptide facilitates late steps in the biogenesis of a bacterial autotransporter.

ABSTRACT: Bacterial autotransporters are proteins that use a C-terminal porin-like domain to facilitate the transport of an upstream "passenger domain" across the outer membrane. Although autotransporters are translocated across the inner membrane (IM) via the Sec pathway, some of them contain exceptionally long signal peptides distinguished by a unique N-terminal sequence motif. In this study, we used the Escherichia coli O157:H7 autotransporter EspP as a model protein to investigate the function of the unusual signal peptides. We found that removal of the N-terminal motif or replacement of the EspP signal peptide did not affect translocation of the protein across the IM. Remarkably, modification of the signal peptide caused EspP to misfold in the periplasm and blocked transport of the passenger do

SUBMITTER: Szabady RL 

PROVIDER: S-EPMC544056 | biostudies-literature | 2005 Jan

REPOSITORIES: biostudies-literature