title: The 245 base-pair oriC sequence of the E. coli chromosome directs bidirectional replication at an adjacent region.
abstract: The replication origin of the E. coli K-12 chromosome has been isolated as autonomously replicating molecules(oriC plasmid), and the DNA region essential for replicating function(oriC) has been localized to a sequence of 232-245 base-pairs(bp) by deletion analysis. In this report, the functional role of oriC was analysed by using an in vitro replication system and various OriC+ and OriC- plasmids previously constructed. The results obtained were summarized as follows: (1) The oriC sequence contained information enough to direct bidirectional replication. (2) The actual DNA replication began at a region near, but outside, oriC and progressed bidirectionally. (3) Initiation of DNA synthesis at the specific region required the dnaA-complementing fraction from cells harboring a dnaA-carrying plasmid.
mesh_terms: D001483:Base Sequence; D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D010957:Plasmids; D013997:Time Factors
chemical_list: D004269:DNA, Bacterial