Alteration in levels of unsaturated fatty acids in mutants of Escherichia coli defective in DNA replication.
We previously reported that mutations in the dnaA gene which encodes the initiator of chromosomal DNA replication in Escherichia coli caused an alteration in the levels of unsaturated fatty acids of phospholipids in membranes. In this study, we examined fatty acid compositions in other mutants which are defective in DNA replication. As in the case of temperature-sensitive dnaA mutants, temperature-sensitive dnaC and dnaE mutants, which have defects in initiation and elongation, respectively, of DNA replication showed a lower level of unsaturation of fatty acids (ratio of unsaturated to saturated fatty acids) compared with the wild-type strain, especially at high temperatures. On the other hand, temperature-sensitive mutants defective in cellular processes other than DNA replication, such as RNA synthesis and cell division, did not show a lower level of unsaturation of fatty acids compared with the wild-type strain. These results suggest that the inhibition of DNA replication causes a lower level of unsaturation of fatty acids in Escherichia coli cells.
Laboratory for Pharmacokinetics, Research and Development Division, Hoechst Marion Roussel, Ltd., Kawagoe, Japan.
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E
Suzuki
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Kondo
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M
Makise
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Mima
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Sakamoto
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T
Tsuchiya
T
T
Mizushima
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D004258:DNA Polymerase III / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000378:metabolism*; D009154:Mutation; D010743:Phospholipids / Q000737:chemistry; D012329:RNA, Bacterial / Q000096:biosynthesis; D013696:Temperature
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; C071702:DnaC protein, E coli; D029968:Escherichia coli Proteins; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D012329:RNA, Bacterial; C074904:DNA polymerase III, alpha subunit; D004258:DNA Polymerase III