Open AccessIncompatibility of outer membrane proteins OmpA and OmpF of Escherichia coli with secretion in Bacillus subtilis : Fusions with secretable peptides
Author(s) -
Simonen Marjo,
Tarkka Eveliina,
Puohiniemi Ritvaleena,
Sarvas Matti
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb14046.x
Subject(s) - bacillus subtilis , escherichia coli , bacterial outer membrane , secretion , escherichia coli proteins , biology , microbiology and biotechnology , enterobacteriaceae , bacillaceae , bacterial protein , bacteria , inner membrane , membrane , biochemistry , gene , genetics
The secretion of the outer membrane proteins OmpA and OmpF of Escherichia coli has previously been found to be blocked at an early intracellular step, when these proteins were fused to a bacillar signal sequence and expressed in Bacillus subtilis . We have now fused these proteins to long secretable polypeptides, the amino‐terminal portions of α‐amylase of β‐lactamase. In spite of this, no secretion of the fusion proteins was detected in B. subtilis . With the exception of a small fraction of the β‐lactamase fusion, the proteins were cell‐bound with uncleaved signal sequences. Protease accessibility indicated that the fusion proteins were not even partially exposed on the outer surface of the cytoplasmic membrane. Thus there was no change of the location compared to the OmpA or OmpF fused to the signal sequence only. We conclude that, like OmpA and OmpF, the fusion proteins fold into an export‐incompatible conformation in B. subtilis before the start of translocation, which we postulate to be a late post‐translational event.