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Biomedical subjects

N I Matvienko

Publications and source records attributed to N I Matvienko.

At least 19 recordsLinked to original sources
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↗
PubMed1992

[Site-specific endonuclease BstM6I from Bacillus stearothermophilus M6].

A site-specific endonuclease activity was found in extract of Bacillus stearothermophilus M6 isolated from molasses. The functionally pure enzyme designated as BstM6I was obtained by consecutive chromatographies on blue sepharose, hydroxyapatite, and heparin-sepharose. The endonuclease recognizes the nucleotide sequence CC decreases WGG in double-stranded DNA and cleaves it as indicated by the arrow to give one-nucleotide 5'-protruding ends. Consequently, the site-specific endonuclease BstM6I is an isoshizomer of BstNI.

Base Sequence↗
PubMed1990

[Cloning and nucleotide sequence determination of the fus gene coding for the elongation factor G of Thermus thermophilus HB8].

A clone with the Thermus thermophilus HB8 fus gene coding for elongation factor G has been identified in a genomic library in plasmid pBR 322 by hybridization with labeled oligonucleotide 19 bases that are complementary in length to the 3'-end of the T. thermophilus fus gene. The fragment with the fus gene was recloned into the pTZ 18R plasmid. A restriction map of this fragment has been made. A set of short overlapping fragments of the fus gene has been obtained by nucleotide sequence unspecific linearization of the plasmid and by the restriction fragment subcloning into M13 mp18 and mp19 vectors. The nucleotide sequence of the fus gene was determined by the dideoxy chain termination method. Fus gene codes the elongation factor G 690 amino acids in length (Mr = 76756 Da). The amino acid sequence of EF-G from T. thermophilus has a 59.7% homology with that of E. coli and a 29.0% homology with EF-2 of rat liver.

Amino Acid Sequence↗
PubMed1989

[Features of expression of cloned genes under the control of tandem promotors pL and pR of phage lambda].

The regulatory block P'R from the bacteriophage lambda has been inserted between the promoter and initial part of the gene into the plasmid pCJ55 carrying the gene for the Klenow fragment under the control of pL. As it should be predicted, at the inverted orientation the sharp decrease in the Klenow fragment quantity is registered. However, at the direct orientation there is some decrease in the synthesis of the protein, as compared with the synthesis of the Klenow fragment in the strain harbouring the plasmid pCJ55. A plausible explanation of the fact may be in the transcriptional interference of the promoters pL and p'R in artificially constructed structures.

Bacteriophage lambda↗
PubMed1989

[New producers of site-specific endonucleases from microorganisms of the Bacillus genus].

52 strains of Bacillus generum have been tested for production of site-specific endonucleases. The sequence recognized by the enzyme was determined for 23 enzymes, the cleavage site inside the sequence was determined for 5 enzymes. All the enzymes under study were found to be isomers of the known enzymes. The selected strains are peculiar for the high level of site-specific endonucleases content and may be used as producents of the enzymes.

Bacillus↗
PubMed1988

[A new type of cleavage of the recognition site by the site-specific endonuclease Bst 4.4I from Bacillus stearothermophilus 4.4].

A site-specific endonuclease Bst 4.4I was isolated from the cell extract of Bacillus stearothermophilus 4.4 and partially purified by chromatography on Ultragel AcA-44 and heparin-Sepharose. It was shown that the endonuclease cleaves lambda and M13 DNA yielding distinct fragments just as endonucleases of II and III types but, in contrast to them can produce two two-strand cuts separated with 30 to 32 nucleotides in the region of the recognition site.

Base Sequence↗
PubMed1988

[Transactivation of p'R promoter of phage lambda].

The host-vector system for efficient expression of the cloned genes under the control of transactivated promoter p'R of bacteriophage lambda has been elaborated. The Q protein activating p'R promoter is coded by the defective prophage constructed in vitro by means of excision of the late phage genes between the distant sites of the restriction endonuclease MluI and change of the central SalI fragment carrying the kill gene for the kanamycin resistance gene. The general recombination system is impaired during the change, thus the bacteriophage DNA can be obtained from the induced RecA cells as a plasmid DNA. The induction of the prophage results in a sharp increase of beta-lactamase synthesis (30% of soluble cell protein) under the control of p'R promoter in a plasmid derived of pBR322.

Bacteriophage lambda↗
PubMed1987

Isolation and some properties of the site-specific endonuclease and methylase Bme2161 from Bacillus megaterium 216.

The site-specific endonuclease Bme2161 was isolated as a homogeneous preparation by chromatography on phosphocellulose, hydroxyapatite and heparin-agarose. The molecular mass of the enzyme, determined by gel filtration and by electrophoresis under denaturing conditions, was found to be 60 kDa and 30 kDa respectively. These data indicate that the native enzyme consists of two identical subunits. The enzyme recognized the decreases pentanucleotide sequence 5'-GGACC-3' X 3'-CCTGG-5' and cleaves the sequence as indicated by arrows. The increases optimal concentration for endonuclease reaction is 6-7 mM Mg2+. The endonuclease relaxes its specificity in the presence of glycerol or dimethyl sulfoxide at low Mg2+ concentration (1-3 mM). Methylase Bme2161, which protects DNA against endonuclease Bme2161 action by DNA methylation, was isolated from the same bacterial strain.

Bacillus megaterium↗
PubMed1987

[Site-specific endonuclease CauB31 from Chloroflexus aurantiacus B3].

A sequence-specific endonuclease CauB3I has been isolated from cell extracts of Chloroflexus aurantiacus and partially purified by chromatography on heparin-sepharose; the yield was 3000 units per 1 g of cells. The final preparation is free of non-specific nucleases. It is shown that endonuclease CauB3I recognizes 5' T decreases CCGGA 3' sequence in double-stranded DNA and cleaves it as shown by an arrow. Methylation of adenine in the recognition sequence makes it resistant to CauB3I.

Base Sequence↗