isolation and characterization of a plasmid dna and biochemical phlt5 from escherichia coli is a code for a system 3 for type ii restriction and modification.

摘要

the strain of escherichia coli1524a isolated from a patient at the national center for bone marrow transplantation in tunis, tunisia. this strain contains 12 plasmids and was resistant to ampicillin, the incorporation of puc18 vector includes a gene for resistance to the antibiotic.the first part of our work, potre on the isolation and identification of a plasmid of small size susteme 4.8kb) encoding a restriction and modification of typeii. the plasmid was named phlt5 is a plasmid which can replicate in a host, and this facilitates the study of the regulation of the gene which codes for the gene coding for restriction and modification.the plasmid, the gene that encodes the enzyme restriction eco1524i is located on a plasmid present in the strain of eco1524a phlt5. the plasmid is able to replicate in the standard strain of escherichia coli hb101, which presents a high resistance to attack by ph agique. the identification of the genetic material of the enzyme eco1524a made by co transformation.the plasmid in the course of the study of unique sites of cut with restriction enzymes ecori smal, marketed as corv, accl, this makes it possible to determine the sequence of relatively easily.