A Mutant Chaperonin That Is Functional at Lower Temperatures Enables Hyperthermophilic Archaea To Grow under Cold-Stress Conditions.

ABSTRACT:

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Thermococcus kodakarensis grows optimally at 85°C and possesses two chaperonins, cold-inducible CpkA and heat-inducible CpkB, which are involved in adaptation to low and high temperatures, respectively. The two chaperonins share a high sequence identity (77%), except in their C-terminal regions. CpkA, which contains tandem repeats of a GGM motif, shows its highest ATPase activity at 60°C to 70°C, whereas CpkB shows its highest activity at temperatures higher than 90°C. To clarify the effects of changes in ATPase activity on chaperonin function at lower temperatures, various CpkA variants were constructed by introducing single point mutations into the C-terminal region. A CpkA variant in which Glu530 was replaced with Gly (CpkA-E530G) showed increased ATPase activity, wit

SUBMITTER: Gao L 

PROVIDER: S-EPMC4507335 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature