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V G Debabov

Publications and source records attributed to V G Debabov.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

[Influence of protein bound with single-stranded DNA on the synthesis of RNA and poly(A). III. Protein product of F1 gene 5].

Influence of the protein product of F1 phage gene 5 (protein 5) on the synthesis RNA and poly(A) in vitro was studied. It has been shown, that protein 5 has no effect on the transcription of the native DNA by E. coli RNA-polymerase, but completely prevents RNA and poly(A) synthesis on the denatured or single-stranded DNA at the protein/DNA ratio 10:1. Protein 5 inhibits poly(A) synthesis with oligo(dT)9 and oligo(dT)12 as a template, preventing binding of enzyme to the oligonucleotide. After the initiation of the poly(A) synthesis the inhibition becomes considerably wearer. The biological function of the inhibition of the transcription by "unwinding" proteins is discussed.

Coliphages↗
PubMedDate not supplied

[Using a combined transcription-translation system for determining the role of cryptic plasmids of Bacillus thuringiensis].

The possibility of entomocyde crystal protein synthesis was studied using a heterological cell-free system with Bacillus thuringiensis plasmid DNA as template. The high level of template activity is usual for Bac. thuringiensis plasmid DNA. Immunochemical studies of the in vitro synthesized polypeptides showed that Bac. thuringiensis plasmid DNA does not direct crystal protein synthesis.

Bacillus thuringiensis↗
PubMedDate not supplied

[Splitting of the DNA of new lambdoid bacteriophages by the specific Eco RI endonuclease].

The number of EcoRI restriction sites in DNAs of several lombdoid phages varies from 2 to 7 and the size of fragments ranges from 0.6 . 10(6) to 25 . 10(6) daltons. Effectiveness of restriction determined in vivo weakly correlates with a number of restriction sites, suggesting different sensitivity of different sites to EcoRI action. No correlation between molecular weights of DNA of different phages and the rate of heat inactivation of the phage has been found. The variability of number of the restriction sites and of the molecular weights of the fragments permits to conclude that: 1) closely-related organisms can be possibly used as convenient sources of certain genes (if a construction of new vector lambdoid phages is essential); 2) there is an opportunity to find phages with different distribution of the restriction sites to other restrictases within a group of phages with non-identical EcoRI restriction sites.

Catalysis↗
PubMedDate not supplied

[Effect of the protein product of phage f1, gene 5, on heat denaturation of synthetic polynucleotides].

The influence of phage f1 gene 5 protein on melting of the synthetic polynucleotides has been investigated, using UV-spectroscopy. In our experiments we have varied the proteins concentration. It has been shown, that the protein lowers the melting temperature of the studied polynucleotides (d/A--Tn dAndTn, rAndTn, rAn.r n, dAn.rn). The melting temperatures and the shapes of melting curves of various polynucleotides differ when the same protein concentrations are used. We have shown that the protein binds to the double-stranded polynucleotides, containing ribo-ribo-, deoxyribo-ribo-chains. The difference in melting temperatures and shapes of melting curves was explained using the data about the differences in the secondary structure of these polynucleotides. Only for d/A-Tn renaturation was observed after sample cooling. It may reflect the single-stranded hairpin structure of this polynucleotide.

Bacteriophages↗
PubMedDate not supplied

[Plasmids of Bacillus thuringiensis var. galleriae strain 612].

We studied Bacillus thuringiensis var galleriae, strain 612 plasmids. B. thuringiensis cells contain double-stranded plasmid DNA molecules (ranging of about 12% from total DNA content) with buoyant density 1.59 g/cm3. Plasmid DNA content was constant during the exponential and stationary phases of bacterial growth. The plasmid fractions consist of DNA molecules with molecular weights of 5.9 x 10(6), 10.0 x 10(6), and 110.9 x 10(6) daltons (pVD1, pVD2 pVD3, respectively). Endonuclease EcoRI cuts the plasmids pVD2 and pVD3 into two and four fragments, respectivelyy, but pVDI seemed to be resistent to EcoRI treatment. We found that pVD2 and pVD3 plasmids contain a common DNA fragment with the molecular weight of 6.7 x 10(6) dalton as it was shown by restriction analysis. In contrast, the same plasmids contain the common fragment with molecular weight of 7.5 x 10(6) dalton as shown by heteroduplex analysis. Plasmid pVD3 has a transposon-like structure.

Bacillus thuringiensis↗
PubMedDate not supplied

[Complex of single-stranded phage DNA and protein--a product of bacteriophage fl gene 3. Distribution of gene 3 protein in the DNA molecule].

Upon a 50% isopropanol treatment of phage fl in a 1 M NaCl solution protein A (gene 3 product)--DNA complex is precipitated while protein B (gene 8 product) was still solubilized. After such a treatment the DNA--protein complex containing 10--40% of protein A and less than 0.0025% of protein B was obtained. Evidence was obtained that there was no non-specific rearrangement of protein A during the isolation procedure. The complex was treated with endonuclease R.HAC III, followed by electrophoresis of the resulted fragments and estimation of the [14C] protein A (labeled with [14C]histidine) throughout the gel. The maximal radioactivity coincided with the DNA bands, being proportional to the DNA content in the respective bands. The data obtained indicate that protein A is iniformly arranged along the DNA molecule.

Chemical Phenomena↗
PubMedDate not supplied

[Influence of proteins bound to single-stranded DNA on RNA and poly(A) synthesis. II. Protein--product of T4 phage gene 32].

It has been shown that the protein product of T4 bacteriophage gene 32 (protein 32) completely prevents RNA and poly(A) synthesis on the denatured DNA as a template at the protein/DNA ratio about 13:1. Under the same conditions protein 32 has no effect on these syntheses on the native DNA and inhibit poly(A) synthesis with oligo(dT)9 and oligo(dT)12 as a template, preventing binding of enzyme with oligonucleotide. It is possible that the unwinded regions of double-stranded DNA within transcription complexes are too small to allow cooperative binding of protein 32 or are unavailable for this protein. We suppose that the protein 32 and other "unwinding" protein plays not only "protective" and "structural" roles but also participates in the regulation of template activity of single-stranded DNA regions in the replicative forks.

Coliphages↗