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Biomedical subjects

N P Kovalevskaia

Publications and source records attributed to N P Kovalevskaia.

10 recordsLinked to original sources
PubMed1996

[Novel site-specific endonuclease from Acinetobacter species M strain].

Site-specific endonuclease R. AspMI was isolated and purified to apparent functional homogeneity from Acinetobacter species (strain M). The enzyme recognizes symmetrical DNA sequence 5'-AGG decreases CCT-3' and cleaves it at the site indicated by the arrow forming blind DNA ends. The endonuclease is an isoschizomer of the StuI endonuclease. Cleavage of the DNA site was inhibited by dcm-methylation. AspMI is approximately equal to 30 kD monomer.

Acinetobacter↗
PubMed1995

[Site-specific endonuclease and methylase from thermophilic bacteria of Bacillus species IS4].

The site-specific endonuclease R . BspIS4I and methylase M . BspIS4I have been isolated and purified to functional purity from the thermophilic strain of Bacillus species IS4. R . BspIS4I recognizes sequence [sequence: see text] on the DNA and cleaves it as indicated by the arrows to form single-stranded 4-nucleotide 5'-protruding termini. The enzyme is an isoschizomer of BbvII. M . BspIS4I is related to adenine-specific methylase.

Bacillus↗
PubMed1993

[Isolation and properties of site-specific endonuclease BspTS514I from the thermophilic bacteria Bacillus species TS514].

New site-specific endonucleases BspBS31I, BstBS32I, BspIS41, BstTS5I, BspTS514I were isolated from five thermophilic soil bacteria Bacillus sp. BS31, B. stearothermophilus BS32, Bacillus sp. IS4, B. stearothermophilus TS5, Bacillus sp. TS514. The enzymes are isoschizomers of the restriction endonuclease BbvII. Endonuclease BspTS514I was obtained pure from interfering contaminations by two consecutive chromatographies on blue agarose and hydroxyapatite. The enzyme exhibits a maximal activity at 55 degrees C in 10 mM tris-HCl (pH 9.2), 10 mM MgCl2 and 50 mM NaCl.

Bacillus↗
PubMed1992

[BspLS2I--a new site-specific endonuclease from the thermophilic bacteria Bacillus species LS2].

A new restriction endonuclease BspLS2I was isolated from the thermophilic bacterium Bacillus species LS2 and purified by blue sepharose and hydroxyapatite chromatographies. The enzyme is an isoschizomer of SduI from Streptococcus durans. BspLS2I recognizes the sequence 5' G(G/A/T)GC(C/T/A) decreases C 3' on double-stranded DNA and cleaves it is indicated by the arrow to yield sticky-ended DNA fragments. Maximum catalytic activity of endonuclease was found in 10 mM tris-HCl (pH 7.9) in the presence of 15-30 mM MgCl2 at 50 degrees C. The phage T4 glucosylated DNA is not cleaved by the enzyme.

Bacillus↗
PubMedDate not supplied

[Mobile gene cassettes and DNA integration elements ].

Integrons are unique natural systems for capturing and spreading the antibiotic resistance genes among Gram-negative bacteria. Gene transfer into small genomes and into plasmids is via site-specific recombination. Integrons act as receptors of antibiotic resistance cassettes. There are known more than 50 cassettes conferring resistance to beta-lactams, aminoglycosides, trimethoprim, chloramphenicol, streptomycin, and other antibiotics. The structure of integrons and of gene cassettes are described and the mechanisms of capture, mobilization, and expression of cassettes considered.

Anti-Bacterial Agents↗
PubMedDate not supplied

[A new thermophilic strain of Bacillus coagulans--a producer of BcoK1 site-specific endonuclease].

The strain, producing new site-specific endonuclease BcoKI has been found at the screening of the thermophilic bacteria isolated from tobacco. A phenotype characteristic of the strain is given. It has been identified as a new strain Bacillus coagulans. BcoKI, a class-IIS restriction endonuclease has been obtained by three consecutive chromatographies on blue agarose hydroxyapatite and heparin-Sepharose. BcoKI, an isoschizomer of Ksp6321, recognizes the six base non-palindromic sequence 5'CTCTTC3' and cleaves one nucleotide 3' of the 3' cytosine on this strand and four nucleotide 5' of the 5' guanine on the opposite strand to generate a three base 5' overhang.

Autoradiography↗
PubMedDate not supplied

[Isolation and properties of BstBSI restriction endonuclease from the thermophilic soil bacteria Bacillus stearothermophilus BS].

A new restriction endonuclease BstBSI was isolated and purified from the thermophilic soil bacterium Bacillus stearothermophilus BS by the blue sepharose and hydroxyapatite chromatographies. The enzyme is an isoschizomer of SnaI from Sphaerotilus natans C. It recognizes the hexanucleotide GTATAC and cleaves DNA in the center of the sequence. The maximal catalytic activity of the endonuclease is registered in 50 mM tris-HCl (pH 9.0) buffer with the high ionic strength (100 mM NaCl) in the presence of 10 mM MgCl2 at 45 degrees C. Glucosylated DNA of the phage T4 is not cleaved by the enzyme.

Chromatography, Gel↗