Comparison of Single and Multiple Turnovers of SecYEG in Escherichia coli.

ABSTRACT: Precursor proteins are translocated across the cytoplasmic membrane in Escherichia coli by the general secretory, or Sec, pathway. The main components of the pathway are the integral membrane heterotrimeric SecYEG complex and the peripheral membrane ATPase, SecA. In this study, we have applied an in vitro assay using inverted cytoplasmic membrane vesicles to investigate the complex cycle that leads to translocation. We compared the apparent rate constants for nine precursors under two experimental conditions, single turnover and multiple turnovers. For each precursor, the rate constant for a single turnover was higher than for multiple turnovers, indicating that a different step limits the rate under the two conditions. We conclude that the rate-limiting step for a single turnover is an ea

SUBMITTER: Mao C 

PROVIDER: S-EPMC7685557 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature