Abstract
Molecular chaperones DnaK and DnaJ are widely known to act as partner protein during proper folding of various proteines.In Cyanobacteria Synechococcus sp. PCC7942,these chaperones were found to exist as multi-gene family with 3 dnaK(dnaK1,dnaK2,dnaK3) and 4 dnaJ(dnaJ1,dnaJ2,dnaJ3,dnaJ4) homologs.dnaJ1 and dnaJ3 were reported to be essential for nomal growth,with the latter exist as partner the dnaK3 and co-localize of the thylakoid membrane.
In order to elucidate other specific function of DnaJ3,we carried out genetic analysis.Using PCR-mutagenesis to introduce point mutation in non-conserved C-terminal region,we were able to isolate a temperature sensitive mutant resulting from mutation F193L.Moreover,one of the suppressor mutation mapped in the PNPase(Polynucleotide phosphorylase).We are currently analyzing the possible mechanism involved in the suppression of dnaJ3 mutation.
