Open AccessProperties of the α subunit of a Chaperonin from the hyperthermophilic Crenarchaeon Aeropyrum pernix K1
Author(s) -
Son HaeJin,
Shin EunJung,
Nam SooWan,
Kim DongEun,
Jeon SungJong
Publication year - 2007
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2006.00513.x
Subject(s) - chaperonin , biology , recombinant dna , biochemistry , molecular mass , sodium dodecyl sulfate , protein subunit , gel electrophoresis , microbiology and biotechnology , gene , enzyme
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 Ap cpnA 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°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°C was 10.04 (±1.31) μM, and k cat was determined to be 2.21 (±0.11) min −1 for the Ap cpnA monomer. The recombinant Ap cpnA 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.