[Increase in the quantity of highly repetitive sequences in extrachromosomal circular DNAs under inhibition of translation by cycloheximide].

Small polydispersed circular DNA(spcDNA) was isolated from cultivated HeLa cells. Cells were treated by cycloheximide in concentrations of 1 and 50 micrograms/ml. Gradient fractions were dot blotted to nitrocellulose filters and were hybridized with different repetitive DNAs.

[Binding of SSB-protein from Ehrlich ascites carcinoma cells with DNA and polyribonucleotides].

Binding of SSB-protein from Ehrlich ascites tumor to ssDNA from M13 phage leads to its compactization. The structure of the complex at the protein/DNA ratios far from the saturation level looks like "beads-on the string". DNA that was fully saturated with protein forms collapsed globular structure.

[Comparative analysis of the structure of double-stranded RNA from killer strains of Saccharomyces cerevisiae].

Double-stranded RNAs (M and L molecules) of two strains of the killer system Saccharomyces cerevisiae M437 (wild type) and ski-5 (superkiller mutant) were studied by means of electron microscopy and high resolution thermal melting. The M molecules of the ski-5 mutant were by 100 b.p.

[The region of phage T4 W-29 genes: cloning and expression].

The EcoRI fragment of T4 DNA containing the W-29 genes and its subfragments were cloned in the pBR322 and the singlestranded M13 phage. Hybridization with a cloned DNA showed that in T4 infected cells the transcription of the late genes 25-29 depends on the phage-induced RNA polymerase changes and on replication of phage DNA. At a late infection stage one also observes an enhanced transcription of the (early) genes uvsW and uvsY, which depends on viral DNA replication.

[Dibromoethylacetate - a new agent for fixing the unwound regions of DNA. Denaturation maps of mitochondrial DNA from the rat liver].

On the basis of the reaction of dibromoethylacetate with adenine and cytosine at the uncoiled regions of DNA it was possible to fix these molten regions (the degree of denaturation was about 16%) for rat liver mitochondrial DNA. Modification of all accessible adenine and cytosine residues in 0.14 M Na-acetate, pH 5.