title: The replication origin of pSC101: the nucleotide sequence and replication functions of the ori region.
abstract: The nucleotide sequence of a 770-bp ori region of plasmid pSC101 is presented. The sequence shows homologies to some parts of Escherichia coli oriC and phage G4 ori. Several other features are an 80-bp A + T-rich region overlapping a part of the region homologous to oriC, three direct repeats of an 18-bp sequence adjacent to the A + T-rich region, a typical promoter sequence just upstream of the longest open reading frame (ORF) and a long inverted repeat sequence overlapping the putative promoter region. Analysis of successive deletions by BAL31 exonuclease demonstrated that one of the regions homologous to oriC along with the A + T-rich region are essential for autonomous replication of the plasmid. The three 18-bp repeats are responsible for incompatibility phenotype. The region containing the promoter-like sequence is required for expression of a trans-acting function.
mesh_terms: D001483:Base Sequence; D002872:Chromosome Deletion; D003090:Coliphages / Q000235:genetics; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics*; D005816:Genetic Complementation Test; D009154:Mutation; D010957:Plasmids; D013696:Temperature
chemical_list: D004262:DNA Restriction Enzymes