title: Coupling between codon usage, translation and protein export in Escherichia coli.
abstract: Proteins destined for export via the Sec-dependent pathway are synthesized with a short N-terminal signal peptide. A requirement for export is that the proteins are in a translocationally competent state. This is a loosely folded state that allows the protein to pass through the SecYEG apparatus and pass into the periplasm. In order to maintain pre-secretory proteins in an export-competent state, there are many factors that slow the folding of the pre-secretory protein in the cytoplasm. These include cytoplasmic chaperones, such as SecB, and the signal recognition particle, which bind the pre-secretory protein and direct it to the cytoplasmic membrane for export. Recently, evidence has been published that non-optimal codons in the signal sequence are important for a time-critical early event to allow the correct folding of pre-secretory proteins. This review details the recent developments in folding of the signal peptide and the pre-secretory protein.
authors.affiliation: Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA.
authors.forename: Yaramah M
authors.initials: YM
authors.lastname: Zalucki
authors.forename: Ifor R
authors.initials: IR
authors.lastname: Beacham
authors.forename: Michael P
authors.initials: MP
authors.lastname: Jennings
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003062:Codon / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D008954:Models, Biological; D019897:Periplasm / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis / Q000235:genetics* / Q000502:physiology; D017510:Protein Folding; D021382:Protein Sorting Signals / Q000235:genetics* / Q000502:physiology; D021381:Protein Transport / Q000235:genetics; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D000069816:SEC Translocation Channels; D018271:Signal Recognition Particle / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003062:Codon; D029968:Escherichia coli Proteins; D021382:Protein Sorting Signals; D011506:Proteins; D000069816:SEC Translocation Channels; C057842:SecB protein, Bacteria; D018271:Signal Recognition Particle