[Regulatory region of the MS2 phage RNA replicase cistron. Accesibility of MS2 RNA specific fragment to T1 RNAse digestion and chemical modification with kethoxal]. / Reguliatornyi uchastok tsistrona replikazy RNK faga MS2. Dostupnost' Spetsificheskogo fragmenta RNK faga MS2 deistviiu RNKazy T1 i khimicheskoi.

Partial digestion with T1 RNAase and chemical modification with kethoxal were used to study stability of two hairpin in the proposed secondary structure of the functionally active MS2 RNA fragment MS2 R(--53 leads to 6), containing the regulatory region of the phage replicase cistron. Analysis of the products obtained after the above treatments showed that T1 RNAase and kethoxal attacked predominantly the guanosine residues in the hairpin b of the MS2 R(--53 leads to 6). This implies that in contrast to the structurally stable hairpin a of the polynucleotide, hairpin b appears to be more labile and may exist under the present experimental conditions in equilibrium with its open form. The data of the competition experiments demonstrated that the kethoxal modified MS2 R(-53 leads to 6) and shorter polynucleotide MS2 R(-53 leads to-11) obtained from MS2 R(-53 leads to 6) after T1 RNAase digestion failed to bind with MS2 coat protein. The relatively unstable hairpin b region in the polynucleotide MS2 R(-53 leads to 6) is suggested to play essential role in the complex formation.

[Primary structure of the 3'-terminal region of the cloned DNA of the bovine leukemia virus]. / Pervichnaia struktura 3'-kontsevoi oblasti klonirovaniia kDNK virusa bych'ego leikoza.

The nucleotide sequence of the 3'-terminal region of the cloned bovine leukaemia virus cDNA (1474 bp) was elucidated using both Sanger and Maxam-Gilbert techniques. This DNA region contains U3 and R parts of the BLV LTR and an upstream sequence with four open reading frames (ORF) of unknown function. The comparison of the nucleotide substitutions in these ORF with the two variants of proviral BLV DNA suggests that the only pX1 ORF possesses a coding function. The role of the pX1 protein is discussed.

[Primary structure of a fragment of cDNA from phage fr]. / Pervichnaia struktura fragmenta kDNK faga fr.

The nucleotide sequence of a 1392 bp fragment of phage fr cDNA has been determined. The fragment contains 3'-terminal part of the A-protein gene, the complete coat protein gene, and beginning of the replicase gene. A comparison between the sequences of the corresponding genes and regulatory regions from the phage fr and MS2 genomes reveals 320 base changes.

[Localization of an antigenic determinant of recombinant interleukin-2, recognized by monoclonal antibody 13B1]. / Lokalizatsiia antigennoi determinanty rekombinantnogo interleikina-2, uznavaemoi monoklonal'nymi antitelami 13B1.

We suggest a simple approach to localization of antigenic determinants for the monoclonal antibody 13B1 raised against recombinant human interleukin-2. The approach is based on the limited trypsin proteolysis, peptide separation by the O'Farrell method and identification of the peptides, interacting with monoclonal antibodies, and comparison of the charge and length of these peptides with the corresponding values of theoretically possible peptides.

[Cloning and nucleotide sequence of the 5'-flanking area of the human interleukin-2 gene]. / Klonirovanie i nukleotidnaia posledovatel'nost' 5'-flankiruiushchei oblasti gena interleikin-2 cheloveka.

We have cloned human interleukin-2 gene and sequenced its 1'-flanking region (-1940 to -936). The region contains promoter-like structures having a high degree of homology with the real promoter.