Structure and function of the bacterial Sec translocon.
Bacteria and archaea possess a protein complex in the plasma membrane that governs protein secretion and membrane protein insertion. Eukaryotes carry homologues in the endoplasmic reticulum (ER) where they direct the same reaction. A combination of experiments conducted on the systems found in all three domains of life has revealed a great deal about protein translocation. The channel provides a route for proteins to pass through the hydrophobic barrier of the membrane, assisted by various partner proteins which maintain an unfolded state of the substrate, target it to the channel and provide the energy and mechanical drive required for transport. In bacteria, the post-translational reaction utilizes an ATPase that couples the free energy of ATP binding and hydrolysis to move the substrate through the protein pore. This review will draw on genetic, biochemical and structural findings in an account of our current understanding of this mechanism.
Gold
Vicki A M
VA
Department of Biochemistry, University of Bristol, Bristol, UK.
Duong
Franck
F
Collinson
Ian
I
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins