Lon Protease Removes Excess Signal Recognition Particle Protein in Escherichia coli.

ABSTRACT: Correct targeting of membrane proteins is essential for membrane integrity, cell physiology, and viability. Cotranslational targeting depends on the universally conserved signal recognition particle (SRP), which is a ribonucleoprotein complex comprised of the protein component Ffh and the 4.5S RNA in Escherichia coli About 25 years ago it was reported that Ffh is an unstable protein, but the underlying mechanism has never been explored. Here, we show that Lon is the primary protease responsible for adjusting the cellular Ffh level. When overproduced, Ffh is particularly prone to degradation during transition from exponential to stationary growth and the cellular Ffh amount is lowest in stationary phase. The Ffh protein consists of two domains, the NG domain, responsible for GTP hydr

SUBMITTER: Sauerbrei B 

PROVIDER: S-EPMC7317043 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature