HtpG is essential for the thermal stress management in cyanobacteria

FEBS Letters

Nakamoto, Hitoshi¹  Tanaka, Naoki¹ 

[1] Department of Biochemistry and Molecular Biology, Saitama University, Urawa 338-8570, Japan

关键词: Cyanobacterium;    Heat shock protein;    Molecular chaperone;    Hsp90;    HtpG;    Thermotolerance;    Hsp;    heat shock protein;    PCR;    polymerase chain reaction;    OD;    optical density;    ORF;    open reading frame;   

DOI  :  10.1016/S0014-5793(99)01134-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The heat shock protein (Hsp) HtpG is a member of the Hsp90 protein family. We cloned a single-copy gene encoding a homologue of HtpG from the unicellular cyanobacterium Synechococcus sp. PCC 7942. Sequence alignment with HtpGs from other prokaryotes revealed unique features in the cyanobacterial HtpG primary sequence. A monocistronic mRNA of the htpG gene increased transiently in response to heat shock. In order to elucidate the role of HtpG in vivo, we inactivated the htpG gene by targeted mutagenesis. Although the mutation did not affect the photoautotrophic growth at 30 and 42°C, the mutant cells were unable to grow at 45°C. They lost both basal and acquired thermotolerances. These results indicate that HtpG plays an essential role for the thermal stress management in cyanobacteria, the first such an example for either a photosynthetic or a prokaryotic organism.

【 授权许可】

Unknown