Involvement of the Shewanella oneidensis Decaheme Cytochrome MtrA in the Periplasmic Stability of the β-Barrel Protein MtrB

The Shewanella oneidensis outer membrane beta-barrel protein MtrB is part of a membrane-spanning protein complex (MtrABC) which is necessary for dissimilatory iron reduction. Quantitative PCR, heterologous gene expression, and mutant studies indicated that MtrA is required for periplasmic stability of MtrB. DegP depletion compensated for this MtrA dependence.