Premium
Alteration in the contents of unsaturated fatty acids in dnaA mutants of Escherichia coli
Author(s) -
Suzuki Emi,
Kondo Taemi,
Makise Masaki,
Mima Shinji,
Sakamoto Kenji,
Tsuchiya Tomofusa,
Mizushima Tohru
Publication year - 1998
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1998.00777.x
Subject(s) - dnaa , mutant , biology , biochemistry , complementation , escherichia coli , dna replication , degree of unsaturation , mutation , fatty acid , dna , gene , origin of replication , chemistry , chromatography
DnaA protein, the initiator of chromosomal DNA replication in Escherichia coli , has a high affinity for acidic phospholipids containing unsaturated fatty acids. We have examined here the fatty acid composition of phospholipids in dnaA mutants. A temperature‐sensitive dnaA46 mutant showed a lower level of unsaturation of fatty acids (ratio of unsaturated to saturated fatty acids) at 42°C (non‐permissive temperature) and at 37°C (semi‐permissive temperature), but not at 28°C (permissive temperature), compared with the wild‐type strain. Plasmid complementation analysis revealed that the dnaA46 mutation is responsible for the phenotype. Other temperature‐sensitive dnaA mutants showed similar results. On the other hand, a cold‐sensitive dnaAcos mutant, in which overinitiation of DNA replication occurs at low temperature (28°C), showed a higher level of unsaturation of fatty acids at 28°C. Based on these observations, we discuss the role of phospholipids in the regulation of the activity of DnaA protein.