Rate-limiting transport of positively charged arginine residues through the Sec-machinery is integral to the mechanism of protein secretion.

ABSTRACT: Transport of proteins across and into membranes is a fundamental biological process with the vast majority being conducted by the ubiquitous Sec machinery. In bacteria, this is usually achieved when the SecY-complex engages the cytosolic ATPase SecA (secretion) or translating ribosomes (insertion). Great strides have been made towards understanding the mechanism of protein translocation. Yet, important questions remain - notably, the nature of the individual steps that constitute transport, and how the proton-motive force (PMF) across the plasma membrane contributes. Here, we apply a recently developed high-resolution protein transport assay to explore these questions. We find that pre-protein transport is limited primarily by the diffusion of arginine residues across the membrane, particu

SUBMITTER: Allen WJ 

PROVIDER: S-EPMC9110029 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature