The structure of the Sec complex and the problem of protein translocation.
Proteins synthesized in the cytosol either remain there or are localized to a specific membrane and subsequently translocated to another cellular compartment. These extracytosolic proteins have to cross, or be inserted into, a phospholipid bilayer-a process governed by membrane-bound protein transporters designed to recognize and receive appropriate polypeptides and thread them through the membrane. One such translocation complex, SecY/Sec61, is found in every cell, in either the plasma membrane of bacteria and archaea or the endoplasmic reticulum membrane of eukaryotes. Recent structural findings, combined with previous genetic and biochemical studies, have helped to describe how the passage of proteins through the membrane might occur, but several points of uncertainty remain.
Robson
Alice
A
Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, UK.
Collinson
Ian
I
D004926:Escherichia coli / Q000737:chemistry* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D008954:Models, Biological; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D000069816:SEC Translocation Channels
D029968:Escherichia coli Proteins; D000069816:SEC Translocation Channels; C057841:SecY protein, E coli