The AAA+ FtsH Protease Degrades an ssrA-Tagged Model Protein in the Inner Membrane of Escherichia coli.

ABSTRACT: In eubacteria, the tmRNA system frees ribosomes that stall during protein synthesis and adds an ssrA tag to the incompletely translated polypeptide to target it for degradation. The AAA+ ClpXP protease degrades most ssrA-tagged proteins in the Escherichia coli cytoplasm and was recently shown to degrade an ssrA-tagged protein in the inner membrane. However, we find that tmRNA-mediated tagging of E. coli ProW_1-182, a different inner-membrane protein, results in degradation by the membrane-tethered AAA+ FtsH protease. ClpXP played no role in the degradation of ProW_1-182 in vivo. These studies suggest that a complex distribution of proteolytic labor maintains protein quality control in the inner membrane.

SUBMITTER: Hari SB 

PROVIDER: S-EPMC5218843 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature