Biomaterial Database

Effect of Escherichia coli IHF mutations on plasmid p15A copy number. 1997

E Hiszczyńska-Sawicka, and J Kur

Department of Microbiology, Technical University of Gdańsk, Poland.

Four isogenic strains (himAhimD double mutant, himA and himD single mutants, and their wild type counterpart) harboring orip15A plasmid (pACYC184 or pACYC184Amp or pACYC177) show different copy numbers of that plasmid in the early stationary phase of cultivation. The copy number of orip15A plasmid increases about four times in the himAhimD double (65-70 copies per cell) and himD single mutant cells (50-56 copies per cell) and was almost the same in himA mutant (17-18 copies per cell) and wild type cells (14-16 copies per cell). The results suggest that HimD can form homodimers, which are functionally competent for the regulation of orip15A plasmid copy number. Complementation experiments of himAhimD double mutant cells using plasmid carrying himA and himD genes (pPLhiphimA-5) confirm the effect of integration host factor (IHF) absence on increasing the copy number of orip15A plasmid (plasmid producing IHF complemented the defect of IHF mutant). The absence of IHF (using himAhimD double mutant as host) had no effect on the copy number of the pBR322 (oripMB1) plasmid.

UI	MeSH Term	Description	Entries
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
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
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D016296	Mutagenesis	Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.	Mutageneses
D018628	Gene Dosage	The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.	Gene Copy Number,Copy Number, Gene,Copy Numbers, Gene,Dosage, Gene,Dosages, Gene,Gene Copy Numbers,Gene Dosages,Number, Gene Copy,Numbers, Gene Copy
D034982	Integration Host Factors	Bacterial proteins that are used by BACTERIOPHAGES to incorporate their DNA into the DNA of the "host" bacteria. They are DNA-binding proteins that function in genetic recombination as well as in transcriptional and translational regulation.	Integration Host Factor,Host Factor Protein,Integration Host Factor alpha Subunit,Integration Host Factor beta Subunit,Factors, Integration Host,Host Factors, Integration