Influence of DnaK and DnaJ chaperones on Escherichia coli membrane lipid composition.

The content of fatty acids extracted from the membranes of E. coli MC 1061 harboring the wild-type dnaKdnaJ alleles and its delta dnaJ and delta dnaKdnaJ derivatives was compared. It was demonstrated that dodecanoic acid was missing in NPLs fraction extracted from both mutants grown at 42 degrees C. Phospholipids extracted from mutant strains were deprived of hexadecanoic acid methyl ester and octadecanol, the latter being correlated with the presence of octadecanoic acid. The amount of LPS extracted from delta dnaKdanJ mutant was significantly lower when compared with wild-type strain and delta dnaJ mutant.