Properties of the alpha subunit of a Chaperonin from the hyperthermophilic Crenarchaeon Aeropyrum pernix K1.
The gene encoding for a putative thermosome from the hyperthermophilic crenarchaeon Aeropyrum pernix K1 (ApcpnA) was cloned and the biochemical characteristics of the resulting recombinant protein were examined. The gene (accession no. APE0907) from A. pernix K1 showed some homology with other group II chaperonins from archaea. The recombinant ApcpnA protein has a molecular mass of 60 kDa, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and exhibited ATPase activity with an optimum temperature and pH of 90 degrees C and 5.0, respectively. The ATPase activity was found to be dependent on manganese and potassium ions, but not magnesium ion. The K(m) for ATP at pH 5.0 and 90 degrees C was 10.04 (+/- 1.31) microM, and k(cat) was determined to be 2.21 (+/- 0.11) min(-1) for the ApcpnA monomer. The recombinant ApcpnA prevents thermal aggregation of bovine rhodanese and enhances the thermal stability of alcohol dehydrogenase in vitro, indicating that the protein is suitable as a molecular chaperonin in the high-temperature environment.
Son
Hae-Jin
HJ
Department of Biotechnology and Bioengineering, Dong-Eui University, Busan, Korea.
Shin
Eun-Jung
EJ
Nam
Soo-Wan
SW
Kim
Dong-Eun
DE
Jeon
Sung-Jong
SJ
D041522:Aeropyrum / Q000235:genetics / Q000378:metabolism*; D000426:Alcohol Dehydrogenase / Q000378:metabolism; D000818:Animals; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D002417:Cattle; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000378:metabolism; D019766:Genes, Archaeal; D007700:Kinetics; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013696:Temperature; D056405:Thermosomes; D013884:Thiosulfate Sulfurtransferase / Q000378:metabolism
D019843:Archaeal Proteins; D005656:Fungal Proteins; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D000426:Alcohol Dehydrogenase; D013884:Thiosulfate Sulfurtransferase; D018833:Chaperonins; D056405:Thermosomes