Alteration of phospholipid composition by combined defects in phosphatidylserine and cardiolipin synthases and physiological consequences in Escherichia coli.

摘要: Abstract Escherichia coli K-12 derivatives with a common genetic background carrying, either alone or in combination, the pss-1 allele coding for temperature-sensitive phosphatidylserine synthase (A. Ohta and I. Shibuya, J. Bacteriol. 132:434-443, 1977) cls- defective cardiolipin (G. Pluschke et al., Biol. Chem. 253:5048-5055, 1978) were constructed. The phospholipid polar headgroup compositions of these strains significantly different from each other depending on their genotypes growth temperature, whereas membrane characteristics such as total content, fatty acid composition, protein profile, lipopolysaccharide content practically same, suggesting that phenotypes direct consequences abnormalities composition. cls double mutation caused an unusual accumulation phosphatidylglycerol extremely low cardiolipin. was found to give defect, its introduction into mutant resulted enhanced temperature sensitivity growth. Addition broth medium proper concentration sucrose, NaCl, Mg2+, Ca2+ allowed at otherwise nonpermissive but required combined addition sucrose NaCl MgCl2 full 42 degrees C. possible mechanisms physiological mutations are discussed molecular basis. remedial effects culture supplements mutants grow C resulting