A Novel Heat Shock Protein Plays an Important Role in Thermal Stress Management in Cyanobacteria

A novel heat shock gene,orf7.5, which encodes a putative acidic polypeptide of 63 amino acids, was cloned from the cyanobacteriumSynechococcus sp. PCC 7942. Northern blot analysis revealed the presence of 400- and 330-base orf7.5 mRNAs, which were barely detectable in the cells grown at 30 °C but increased transiently in response to heat shock at 40 or 45 °C. Primer extension analysis showed that the two mRNAs have different 5′-ends....