PubMed Health⌕ Search

Biomedical subjects

N I Matvienko

Publications and source records attributed to N I Matvienko.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1983

[Site-specific endonuclease BmeI from Bacillus megaterium 216].

A site-specific endonuclease BmeI has been isolated from Bacillus megaterium 216 by gel filtration on ultragel AcA-44 with a subsequent chromatography on heparin-sepharose 6B. On the double-stranded DNA the endonuclease recognizes the pentanucleotide sequence (Formula: see text); and hydrolyzes it in the points shown by arrows. At gel filtration the endonuclease is eluted in the volume corresponding to a molecular mass of 60 000.

Bacillus megaterium↗
PubMed1976

Construction of a hybrid col E1 plasmid carrying the gene for bacteriophage lambda repressor.

A biologically active hybrid DNA molecule was constructed from plasmid Col E1 and the Eco R1 fragment of lambda DNA containing the gene for lambda repressor. The presence of this gene in the hybrid molecule was demonstrated genetically. The hybrid plasmid contains two closely located targets for restriction endonuclease Hind 111 in the integrated fragment. Thus, the plasmid may be used as a vector not only for Eco R1 fragments but also for Hind 111 fragments.

Colicins↗
PubMed1976

Sepcific fragmentation of DNA heteroduplex molecules of two bacteriophage lambda mutants with endonuclease Si from Aspergillus oryzae.

Heteroduplex DNA molecules of two bacteriophage mutants (lambda b2 and lambda i434ct68) were obtained by the method of molecular hybridization. These heteroduplexes possessed two types of loops formed as a result of: a) deletion in one of the DNA strands; and b) substitution of a DNA fragment for nonhomological one. The digestion of heteroduplexes with single-stranded specific nuclease SI from Aspergillus oryzae produced two fragments at 37 degrees C and three ones at 55 degrees C. The separation of fragments and determination of their molecular weight were carried out by means of electrophoresis in agarose. The molecular weights both measured and preliminarily calculated proved to be close. One of the fragments was identificated by its biological activity in CaCl2-dependent infectious system with helperphage.

Aspergillus oryzae↗