title: Chaperonins: The hunt for the Group II mechanism.
abstract: Chaperonins are multi-subunit complexes that enhance the efficiency of protein-folding reactions by capturing protein substrates in their central cavities. They occur in all prokaryotic and eukaryotic cell types and, alone amongst molecular chaperones, chaperonin knockouts are always lethal. Chaperonins come in two forms; the Group I are found in bacteria, mitochondria and plastids [W.A. Fenton, A.L. Horwich, Q. Rev. Biophys. 36 (2003) 229-256, [1]] and the Group II in the eukaryotic cytoplasm and in archaea [N.J. Cowan, S.A. Lewis, Adv. Protein Chem. 59 (2001) 73-104, [2]]. Both use energy derived from ATP binding and hydrolysis to drive a series of structural rearrangements that enable them to capture, engulf and then release polypeptide chains that have either not yet acquired the native, biologically active state or have been denatured in the cell.
authors.affiliation: Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol B58 1TD, UK. g.bigotti@bristol.ac.uk
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Bigotti
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Clarke
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000494:Allosteric Regulation; D000818:Animals; D001105:Archaea / Q000201:enzymology; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism*; D018360:Crystallography, X-Ray; D006801:Humans; D006868:Hydrolysis; D008854:Microscopy, Electron; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D019843:Archaeal Proteins; D018832:Molecular Chaperones; D021122:Protein Subunits; C112806:prefoldin; D000251:Adenosine Triphosphatases; D018833:Chaperonins