title: Structural and Functional Insights into the Evolution and Stress Adaptation of Type II Chaperonins.
abstract: Chaperonins are essential biological complexes assisting protein folding in all kingdoms of life. Whereas homooligomeric bacterial GroEL binds hydrophobic substrates non-specifically, the heterooligomeric eukaryotic CCT binds specifically to distinct classes of substrates. Sulfolobales, which survive in a wide range of temperatures, have evolved three different chaperonin subunits (α, β, γ) that form three distinct complexes tailored for different substrate classes at cold, normal, and elevated temperatures. The larger octadecameric β complexes cater for substrates under heat stress, whereas smaller hexadecameric αβ complexes prevail under normal conditions. The cold-shock complex contains all three subunits, consistent with greater substrate specificity. Structural analysis using crystallography and electron microscopy reveals the geometry of these complexes and shows a novel arrangement of the α and β subunits in the hexadecamer enabling incorporation of the γ subunit.
authors: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
authors: Jessica J
authors: JJ
authors: Chaston
authors: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
authors: Callum
authors: C
authors: Smits
authors: Australian Synchrotron, Clayton, VIC 3168, Australia.
authors: David
authors: D
authors: Aragão
authors: School of Biological Sciences, Nanyang Technological University, Singapore 637551; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 637551.
authors: Andrew S W
authors: AS
authors: Wong
authors: School of Biological Sciences, Nanyang Technological University, Singapore 637551.
authors: Bilal
authors: B
authors: Ahsan
authors: School of Biological Sciences, Nanyang Technological University, Singapore 637551; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 637551.
authors: Sara
authors: S
authors: Sandin
authors: Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
authors: Sudheer K
authors: SK
authors: Molugu
authors: Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
authors: Sanjay K
authors: SK
authors: Molugu
authors: Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
authors: Ricardo A
authors: RA
authors: Bernal
authors: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia. Electronic address: d.stock@victorchang.edu.au.
authors: Daniela
authors: D
authors: Stock
authors: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia. Electronic address: a.stewart@victorchang.edu.au.
authors: Alastair G
authors: AG
authors: Stewart
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D019143:Evolution, Molecular; D056385:Group II Chaperonins / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008854:Microscopy, Electron; D008958:Models, Molecular; D010802:Phylogeny; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D013379:Substrate Specificity; D048229:Sulfolobus solfataricus / Q000378:metabolism*; D013696:Temperature
chemical_list: D019843:Archaeal Proteins; D056385:Group II Chaperonins