title: Allosteric Mechanisms in Chaperonin Machines.
abstract: Chaperonins are nanomachines that facilitate protein folding by undergoing energy (ATP)-dependent movements that are coordinated in time and space owing to complex allosteric regulation. They consist of two back-to-back stacked oligomeric rings with a cavity at each end where protein substrate folding can take place. Here, we focus on the GroEL/GroES chaperonin system from Escherichia coli and, to a lesser extent, on the more poorly characterized eukaryotic chaperonin CCT/TRiC. We describe their various functional (allosteric) states and how they are affected by substrates and allosteric effectors that include ATP, ADP, nonfolded protein substrates, potassium ions, and GroES (in the case of GroEL). We also discuss the pathways of intra- and inter-ring allosteric communication by which they interconvert and the coupling between allosteric transitions and protein folding reactions.
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Ranit
authors.initials: R
authors.lastname: Gruber
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Amnon
authors.initials: A
authors.lastname: Horovitz
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000494:Allosteric Regulation; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D011188:Potassium / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D029968:Escherichia coli Proteins; D000255:Adenosine Triphosphate; D018833:Chaperonins; D011188:Potassium