title: The Escherichia coli groE chaperonins.
abstract: The E.coli groES and groEL genes have been shown to form an operon, to be essential for E. coli viability, and to belong to the so-called heat-shock class of genes whose expression is regulated by the intracellular levels of sigma factor sigma 32. Both groE chaperonin proteins possess a seven-fold axis of symmetry, groES being composed of seven identical subunits of 97 amino acids each, and groEL of fourteen identical subunits of 548 amino acids each. The two groE chaperonins interact intimately as judged by both genetic and biochemical criteria. This interaction has been shown to be required for both bacteriophage morphogenesis and bacterial growth. The groEL chaperonin has been shown to bind to a number of incomplete or unfolded polypeptides in vitro. Such binding may prevent misfolding and promote rapid intra- or intermolecular folding of polypeptides in vivo. The proposed role of the groES chaperonin is to displace the polypeptides bound to groEL, thus effectively promoting the recycling of groEL.
authors.affiliation: Department of Cellular, Viral and Molecular Biology, University of Utah Medical Center, Salt Lake City 84132.
authors.forename: C
authors.initials: C
authors.lastname: Georgopoulos
authors.forename: D
authors.initials: D
authors.lastname: Ang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D018835:Chaperonin 10; D018834:Chaperonin 60; D018833:Chaperonins; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000502:physiology; D011485:Protein Binding; D011506:Proteins / Q000235:genetics* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D018835:Chaperonin 10; D018834:Chaperonin 60; D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D006360:Heat-Shock Proteins; D011506:Proteins; D018833:Chaperonins