[Interaction of tripeptides containing arginine and tyrosine (or phenylalanine) residues with synthetic polynucleotides and DNA of various origins]. / Issledovanie vzaimodeistviia tripeptidov, soderzhashchikh ostatki arginina i tirozina (ili fenilalanina), s sinteticheskimi polinukleotidami i DNK razlichnogo proiskhozhdeniia.

Model peptides--L-Arg-Gly-L-Arg, L-Arg-L-Tyr-L-Arg and L-Arg-L-Phe-L-Arg bind to different DNAs and synthetic polynucleotides and are found in the major groove of the double helix. Polynucleotide complexes containing L-Arg-Gly-L-Arg were studied in order to consider the influence of the arginine residues on the polynucleotide melting temperature. It was shown, that L-Arg-L-Tyr-L-Arg and L-Arg-L-Phe--L-Arg lowers the melting temperature in all polynucleotides studied. The dependence of the melting temperature of polynucleotide (DNA)--L-Arg-L-Tyr(L-Phe)-L-Arg complexes upon the polynucleotide GC-content has been detected. These effects reflect the intercalation of peptide tyrosyl (or phenylalanyl) residues into the double-stranded polynucleotide.

[Interaction of the peptide antibiotic bacitracin with DNA and synthetic polynucleotides]. / Issledovanie vzaimodeistviia peptidnogo antibiotika batsitratsina s DNK i sinteticheskimi polinukleotidami.

The aim of the present paper was to study the specific character of interaction of peptide antibiotic bacitracin with DNA and to estimate the interaction constant. The influence of bacitracin on bacteriophage DNA restriction by HindIII and SmaI endonucleases was studied. The possibility of arranging the polynucleotide template by small ligands was shown.

B-Z transition in poly(dG-dC).poly(dG-dC) in the presence of formaldehyde amino derivatives.

It was shown by circular dichroism that the B-Z transition of poly(dG-dC).poly(dG-dC) in high NaCl concentrations occurred more rapidly in the presence of formaldehyde and Tris. The product of formaldehyde and glycine interaction induces changes in the poly(dG-dC).poly(dG-dC) CD spectral characteristics of a 'B-like' conformation. It is supposed that the B-Z transition occurs without large-scale hydrogen bond breakage.

[Possible mechanism of specific protein-nucleic acid interaction]. / Vozmozhnyi mekhanizm spetsificheskogo belok-nukleinovogo vzaimodeistviia.

It has been supposed that stereochemical fitness of amino acids into the cavities associated with their codons is used for specific recognition of nucleic acids by the proteins. In accordance with this hypothesis, amino acid side chains can insert into the cavity resulting from inverting the middle base of a nucleotide triplet in DNA. Certain experimental data seem to support the hypothesis. A model of specific binding between cro-protein from bacteriophage lambda with OR3 operator region of the bacteriophage has been proposed on the basis of the above hypothesis.

[Sporulation in Bacillus licheniformis during altered bacitracin synthesis]. / Sporoobrazovanie u Bacillus licheniformis pri izmenenii sinteza batsitratsina.

Sporulation in different strains of Bacillus licheniformis, 10716 and 1001 in connection with changes in synthesis of bacitracin was studied. It was shown that the sporulation efficiency did not depend on the synthesis of the antibiotic: in some strains with low potency for the antibiotic production, the sporulation level was lowered, while in the others, it was not lowered. Moreover, normal sporulation was also observed, when the synthesis of bacitracin was inhibited. Therefore, it is suggested that there is no correlation between the sporulation and antibiotic production.

[The role of peptide antibiotics in the regulation of cell differentiation in bacteria]. / Rol' peptidnykh antibiotikov v reguliatsii kletochnoi differentsiatsii u bakterii.

The literature data and the results of the experiments performed by the authors on possible participation of peptide antibiotics in regulation of cell differentiation in bacteria were analysed. It was shown that the available experimental data were in conformity with the regulatory hypothesis. According to this hypothesis the biological role of peptide antibiotics lies in participation in the control of sporulation and germination of the spores rather than in protection upon competition of different microorganisms in nature.

[Physico-chemical properties of the complexes of bacitracin with DNA and its effect on the process of transcription in vitro]. / Fiziko-khimicheskie svoistva kompleksov batsitratsina s DNK i vliianie ego na protsess transkriptsii in vitro.

The aim of the present paper was to study the action of one of the peptide antibiotics, bacitracin, as the regulator of gene activity at the transcription level. Therefore the commercial bacitracin has been fractionated into two main parts by paper chromotography. These two fractions have been identified as bacitracin A (biologically active) and bacitracin F (biologically inactive). The binding of both fractions to DNA has been studied. It has been shown that bacitracin A stabilizes DNA to a lesser degree than bacitracin F does. DNA-bacitracin complexes are formed in the major groove of the DNA helix by hydrogen bonds. The analysis of the the obtained experimental data allows us to suppose that bacitracin binding to DNA has a very specific character and that this antibiotic may act as the regulator of gene activity.

[Study of the mechanism of the unwinding effect of destabilized helix of bacteriophage f1 gene 5 protein with the aid of model tripeptides]. / Issledovanie mekhanizma raspletaiushchego deistviia destabiliziruiushchego spiral' belka gena 5 bakteriofaga f1 s pomoshch'iu model'nykh tripeptidov.

Complexes of synthetic double-stranded polynucleotides and DNA with model peptides--L-Lys-L-Tyr-L-Lys and L-Lys-Gly-L-Lys have been investigated, using UV-spectroscopy. Polynucleotide complexes containing L-Lys-Gly-L-Lys were studied in order to consider the influence of lysyl residues on the polynucleotide melting temperature. It was shown, that L-Lys-L-Tyr-L-Lys lowers the melting temperature of all the polynucleotides studied, except poly(rI) . poly(C). The dependence of melting temperature of polynucleotide (DNA) . L-Lys-L-Tyr-L-Lys complexes upon the polynucleotide double helix form and GC-content has been detected. These effects have reflected the intercalation of peptide tyrosyl residues into one of the chains of the double-stranded polynucleotide. Correlation o the melting temperature dependences of polynucleotide complexes with gene 5 protein and L-Lys-L-Tyr-L-Lys upon polynucleotide double helix form and GC-content was found.

[Effect of dioxidine on DNA and RNA synthesis in Staphylococcus aureus]. / Vliianie dioksidina na sintez DNK i RNK u zolotistogo stafilokokka.

The effect of dioxidin on DNA and RNA synthesis by Staphylococcus aureus was studied with the use of labeled precursors and evaluated from the kinetics of DNA and RNA accumulation by the culture. It was shown that dioxidin inhibits DNA synthesis by Staphylococcus aureus cells, with the synthesis of RNA being almost not affected. The main effect manifests within the first hour of the drug interplay with the microbial cell, it is reversible and appears to be realized by the mechanisms of DNA synthesis regulation. Dioxidin does not form complexes or cross-linkages with the DNA molecule. The action of dioxidin on the microbial cell manifests in the derangement of the activity and biosynthesis of extracellular DNase.

[Pseudomonas aeruginosa phages whose DNA structure is similar to the DNA structure of phage Mu 1. III. The isolation and analysis of the hybrid phages D3112 and B39: localization of the immunity region and of certain genetic factors]. / Bakteriofagi Pseudomonas aeruginosa, struktura DNK kotorykh skhodna so strukturoi DNK faga Mu 1. Soobshchenie III. Vydelenie i analiz gibridov fagov D3112 i B39: lokalizatsiia oblasti immuniteta i nekotorykh geneticheskikh faktorov.

Several different hybrids have been isolated in a cross between heteroimmune Mu-like Pseudomonas aeruginosa bacteriophages D3112 and B39. Analysis of hybrid phage DNAs treated with specific endonucleases and heteroduplex studies have permitted to map the immunity region of phages in the left part of their genomes. Also, a ts-mutation in the wild-type B39 and some genetic factors influencing the growth of D3112 in P. aeruginosa strain PA0 (B39) and in bacteria harbouring RPL11 plasmid, have been localized. All recombinants studied have arisen by double crossingover and can be considered as substitutions of different continuous parts of the D3112 genome by fragments of the B39 genome. A comparison of distribution of non-homologous regions in B39 and D3112 genomes as well as locations of endonuclease-sensitive sites have given some unexpected results. In contrast to the B39-D3112 pair, the other pair of related Mu-like phages, B3-D3112, have no visible homology within the most part of their genomes.

[Study of fusion of bacteriophage f2 double-stranded RNA, poly(A).poly(U), and poly(G).poly(C) in the presence of tetraethylammonium bromide]. / Issledovanie plavleniia dvukhtsepochechnoi RNK bakteriofaga f2, poli (A).polu(U) and poli(G).poli (C) v prisutstvii bromistogo tetraétilammoniia.

The data on the dependence of the melting curve parameters of double-stranded RNA (replicative form of RNA of f2 bacteriophage) poly(A) times poly(U) and poly(G) times poly(C) on the concentration of (C2H5)4NBr were obtained. The RNA melting range width is shown to pass through the minimum value T =2.1+/-0.1degrees at the point of inversion of relative stability of GC and AU pairs that corresponds to 4.0+/-0.1 M concentration of (C2H5)4NBr. Using the melting temperatures of poly(A) times poly(U) and poly(G) times poly(C) the rependence of Tgc-Tau parameter on (C2H5)4NBr concentration was shown. It was concluded from these data that the effect of the double-stranded RNA stacking heterogeneity was negligible in the 0-3 M range of (C2H5)4NBr concentration. Melting curves of RNA were obtained at various values of Tgc-Tau parameter. It was shown that the profile of fine structure of melting curves depends on the value of Tgc-Tau parameter.

[Certain physico-chemical properties of bacteriophage phiKZ]. / Nekotorye fiziko-khimicheskie svoistva bakteriofaga phiKZ.

Using UV-spectroscopy and circular dichroism (CD) phi KZ bacteriophage and its DNA were investigated. From the value of optical densities in the 320--400 nm range the size of the phi KZ bacteriophage's head was determined; the diameter of phi KZ bacteriophage head was found to be equal to 1300 +/- 100 A. phi KZ bacteriophage DNA has block structure and the GC-pair content is equal to 43.8 +/- 0.3%. phi KZ bacteriophage CD spectrum has an unusual profile (in comparison with known bacteriophage CD spectra); this spectrum is similar to the CD spectra of DNA in polyethylene glycole solution. To our knowledge CD spectra of such type were not obtained for other bacteriophages.

[Circular dichroism study of the reaction between the protein product of bacteriophage f1 gene 5 and synthetic polynucleotides]. / Izuchenie vzaimodeistviia belka--produkta gena 5 bakteriofaga f1 s sinteticheskimi polinukleotidami metodom krugovogo dikhroizma.

The complexes of gene 5 protein (phage f1) with single-stranded and double-stranded polynucleotides were investigated by circular dichroism (CD). In our experiments the concentration of the protein varied accordingly to polynucleotide. A decrease of the CD amplitude for polynucleotide-protein complexes was shown in all the regions of wavelength studied. The data indicate that the protein is bounded to the polynucleotide. This protein bounds differently to double-stranded polynucleotides containing ribo-ribo, ribo-deoxyribo and deoxyribo-deoxyribo chains. This difference is explained by differences in the form of the secondary structure of polynucleotides, containing ribo-ribo, ribo-deoxyribo and deoxyribo-deoxyribo chains.

[Physical map of the DNA of bacteriophage phiB]. / Fizicheskaia karta DNK bakteriofaga phiB.

A physical map of DNA phi B bacteriophage was constructed. Using the data of denaturation maps and heteroduplex analysis the positions of 10 (from 11) peaks were estimated. These peaks belong to DNA regions obtained after hydrolysis of phi B DNA by EcoRI endonuclease. This map is orientated to the end of the DNA molecule, which first entered the head, during phage maturation. The disposition of AT-enriched regions of the DNA molecule were shown.

[Control of plasmid incompatibility: characteristics of the bireplicon hybrid pAS8 and its deletion mutants]. / Kontrol' plazmidnoi nesovmestimosti: kharakteristika dvureplikonnogo gibrida pAS8 i ego deletsionnykh mutantov.

The phenomenon of incompatibility has been investigated using deletion mutants of hybrid bireplicon plasmid pAS8. The hybrid pAS8 displays incompatibility specific for both components of its structure. In contrast to P-specificity of pAS8, functions of ColE1-specificity are not effectively expressed. Expression of ColE1-specificity in pAS8 plasmid and its derivatives is characterized by different directions and this is due to the presence or absence of genes of RP4 replication machinery in the plasmid DNA. Mutant plasmids show different efficiency of P-specificity depending on the extension of deletion in the region of essential genes of the RP4 component. Some of the mutants, in spite of the loss of replication genes, including origin of vegetative replication, are incompatible with the representatives of the Inc P group in both directions of testing. Different character and the level of expression of ColE1- and P-specificity in the pAS8 hybrid and its deletion derivatives are not associated with change in the number of plasmid DNA copies, for all of them are subjects to stringent control of replication. The data suggest the existence of incompatibility functions control mechanism which does not seem to include replication genes. Possible ways of realization of the inc genes functions are discussed.

[Unwinding effect of F1 gene 5 protein on double-stranded polynucleotides and DNA]. / K voprosy o mekhanizme raspletaiushchego deistviia belka gena 5 faga fl.

The effect of gene 5 protein from bacteriophage f1 on melting of double-stranded polynucleotides and DNAs has been investigated using the UV-spectroscopy method. A dependence of the melting temperature of polynucleotide (DNA)-gene 5 protein complexes upon the polynucleotide (DNA) GC-pair content has been detected. Using experimental data and examining some model systems we came to the supposition that the lowering of melting temperature of polynucleotide (DNA) induced by this protein is probably stipulated by intercalation of the protein tyrosyl residues into one of the chains of polynucleotide (DNA) double helix.

Denaturation maps of DNA: experimental and theoretical maps of phiX174 DNA.

A formaldehyde denaturation map of the replicative form of phiX174 DNA is obtained. The RFI DNA was converted into a linear state by restriction endonuclease pst I which introduces into this DNA a single double-stranded break. The map has four clear-cut peaks. Their positions excellently correlate with the peak positions on the map of equilibrium denaturation theoretically obtained earlier from the known nucleotide sequence of phiX174 DNA. The sequence is also used for a calculation of the maps of smoothed AT-content. The maxima on these maps correlate well with the peaks on the denaturation maps. To reveal the causes of a good correlation between the experimental formaldehyde and theoretical equilibrium denaturation maps, the theoretical formaldehyde denaturation maps are calculated for different conditions (temperature, formaldehyde concentration) using the detailed theory of DNA interaction with formaldehyde developed earlier.

[Nature of the easily melted portions of DNA with a quasi-random base sequence]. / O prirode legkoplavkikh uchastkov DNK s kvazisluchainoi posledovatel'nost'iu osnovanii.

The influence of denaturation conditions upon the character of partial denaturation of DNA with random base distribution were thoroughly studied. Maps of partial DNA denaturation were obtained at T less than TAT for phage phiB DNA at pH 10.7 and 5.5; Tg9 DNA at pH 8.8; at T less than TAT for phiB DNA at pH 10.9 and Tg9 DNA at pH 8.8. The map quality was better when obtained at higher pH values; the peaks became sharper and higher against the background. We failed to obtain maps of partial denaturation at pH 5.5, T less than TAT. The improvement of the map quality and existence of the partial denaturation maps at T less than TAT at pH 10.9 were explained by the increase of primary melting probability of AT-rich DNA regions. At high pH the denaturation map quality was temperature independent. This was explained by a very weak temperature dependence of primary melting probability for all maps of equal quality. The map quality became worse, when the quantity of loops was increased.