Biomaterial Database

[High plasmid pBR322 multimerization in Escherichia coli B]. 1993

L G Viacheslavov, and M I Mosevitskiĭ

In bacteria E. coli B (wild) plasmid pBR322 is present as a set of circular supercoiled multimers formed of up to 20 head-to-tail linked monomers. The highest degree of plasmid multimerization was achieved when the bacteria were grown in a mineral-glucose medium based on 0.15 M phosphate buffer (pH 7.5). In E. coli K12 grown under similar conditions, plasmid pBR322 was mainly present as monomers. A kinetic experiment (initially only monomeric plasmids were present in the cells) has shown that multimerization of plasmids occurs step by step, that is, by means of interplasmid recombinations. Therefore, in E. coli B the efficiency of interplasmid recombinations is higher in comparison with E. coli K12. This result reflects some differences between basic systems of genetic recombination operating in these two lines of E. coli.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D011995	Recombination, Genetic	Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.	Genetic Recombination,Recombination,Genetic Recombinations,Recombinations,Recombinations, Genetic
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli