Protein secretion Sec translocation machinery (Sec machinery (SecYEG complex in bacteria; Sec61 complex in eukaryotes))

The Protein secretion Sec translocation machinery is a highly conserved protein complex that mediates the export of unfolded polypeptides across cellular or organellar membranes. In bacteria, it consists primarily of the SecYEG channel and the SecA ATPase motor, which threads proteins through a membrane pore using ATP hydrolysis and the proton gradient as energy sources. Precursor proteins are directed to the complex by N-terminal signal sequences, kept unfolded by chaperones (such as SecB), and translocated through SecYEG (bacteria) or Sec61 (eukaryotes), either post-translationally or co-translationally. This machinery is essential for bacterial viability and the secretion of pathogenic factors, representing an attractive target for new classes of antibiotics.

Other names

Sec translocaseSecYEG complex (bacteria)SecA-SecY complex (bacteria)Sec61 complex (eukaryotes)Protein-conducting channelSec system

Inhibition of SecA ATPase activity (blocks energy-dependent translocation); Disruption of SecYEG complex function (prevents protein export and cell wall protein localization)