RRC ID 30128
著者 Asai T, Imai M, Kogoma T.
タイトル DNA damage-inducible replication of the Escherichia coli chromosome is initiated at separable sites within the minimal oriC.
ジャーナル J Mol Biol
Abstract When Escherichia coli cells are subjected to genetic stress by exposure to agents or conditions that transiently block DNA replication, the mode of DNA replication is profoundly altered. One of the alterations is the induction of inducible stable DNA replication (iSDR) that does not require the initiator protein, DnaA, and occurs despite the presence of rifampin and chloramphenicol, which inhibit the initiation of usual chromosome replication at oriC. It has been demonstrated that iSDR starts primarily from both the oriC and terC regions of the chromosome. To precisely map the iSDR origin (oriM1) located in the oriC region, various oriC fragments were inserted into a plasmid vector derived from pSC101, and the copy number of these plasmid constructs was measured in the presence of rifampin and chloramphenicol after cells were induced for the SOS response by thymine starvation. The results indicated that there are at least two origins for iSDR within the minimal oriC; one (oriM1A) is located between the BamHI (coordinate +1) and the AvaII(155) sites, and the other (oriM1B) between the AvaII(155) and the HindIII(244) sites. Furthermore, a 263 bp fragment containing oriM1, which was placed at the att lambda site of the chromosome, was found to initiate chromosome replication in the presence of the drugs when cells were starved of thymine. Introduction of additional copies of oriM1 into a cell stimulated initiation of iSDR at oriM1 on the chromosome. The result supported the model that iSDR starts from D-loops created between oriM1 sequences and that the amount of D-loops determines the level of the iSDR activity.
巻・号 235(5)
ページ 1459-69
公開日 1994-2-4
DOI 10.1006/jmbi.1994.1101
PII S0022-2836(84)71101-6
PMID 8107086
MeSH Bacterial Proteins / metabolism Blotting, Southern Chloramphenicol / pharmacology Chromosomes, Bacterial* DNA Damage* DNA Replication / drug effects DNA Replication / genetics* DNA, Bacterial / analysis DNA, Bacterial / biosynthesis DNA-Binding Proteins / metabolism Escherichia coli / drug effects Escherichia coli / genetics* Escherichia coli / metabolism Genetic Vectors Genotype Kinetics Plasmids Restriction Mapping Rifampin / pharmacology SOS Response, Genetics* Thymine / metabolism Time Factors
IF 4.76
引用数 13
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌) ME9385