title: Gly-345 plays an essential role in Pyrococcus furiosus chaperonin function.
abstract: Compared to the group I chaperonins, such as Escherichia coli GroEL, which facilitate protein folding, many aspects of the functional mechanism of archaeal group II chaperonins are unclear. Sequence homology between the chaperonin from Pyrococcus furiosus (PfCPN) and other group II chaperonins, together with the homo-oligomeric nature of PfCPN, suggest that PfCPN may serve as a model to clarify the role of the homologous position Gly-345 in the chaperonin-mediated protein folding. Here, we show that the purified chaperonin mutant in which the conserved residue Gly-345 is replaced by Asp (G345D) displays only about 25% ATP/ADP hydrolysis activities of the wild-type in the presence of Co(2+) and has a reduced capacity to promote folding of denatured malate dehydrogenase in vitro. This may be a reflection that Gly-345 plays an essential role in conformational change and protein refolding by archaeal group II chaperonins.
authors.affiliation: Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 500 Caobao Road, Shanghai, China.
authors.forename: Li-da
authors.initials: LD
authors.lastname: Yang
authors.forename: Zhong-Mei
authors.initials: ZM
authors.lastname: Chu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Sheng-Li
authors.initials: SL
authors.lastname: Yang
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D005998:Glycine / Q000737:chemistry*; D056385:Group II Chaperonins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D017510:Protein Folding; D020027:Pyrococcus furiosus / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D019843:Archaeal Proteins; D011994:Recombinant Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D056385:Group II Chaperonins; D005998:Glycine