Dimer recognition and secretion by the ESX secretion system in Bacillus subtilis.


Journal Article

Protein secretion typically involves translocation of unfolded polypeptides or transport of monomeric folded proteins. Here we provide, to our knowledge, the first experimental evidence for secretion of an intact multimeric complex requiring a signal formed by both members of the complex. Using systematic mutagenesis of a substrate involved in early secretory antigen 6 kDa (ESX) secretion in Bacillus subtilis, we demonstrate that export of the substrate requires two independent motifs. Using mixed dimers, we show that these motifs must form a composite secretion signal in which one motif is contributed by each subunit of the dimer. Finally, through targeted crosslinking we show that the dimer formed in the cell is likely secreted as a single unit. We discuss implications of this substrate recognition mechanism for the biogenesis and quality control of secretion substrates and describe its likely conservation across ESX systems.

Full Text

Cited Authors

  • Sysoeva, TA; Zepeda-Rivera, MA; Huppert, LA; Burton, BM

Published Date

  • May 14, 2014

Published In

Volume / Issue

  • 111 / 21

Start / End Page

  • 7653 - 7658

PubMed ID

  • 24828531

Pubmed Central ID

  • 24828531

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.1322200111


  • eng