[Determination and comparative analysis of the nucleotide sequence for minireplicon fragments of the cryptic plasmid p1414 from the soil strain of Bacillus subtilis]. / Opredelenie i sravnitel'nyi analiz nukleotidnoi posledovatel'nosti fragmentov minireplikona kripticheskoi plazmidy p1414 iz pochvennogo shtamma Bacillus subtilis.

Nucleotide sequences of two minireplicon fragments of the p1414 cryptic plasmid of Bacillus subtilis were determined. The fragments corresponded to the region containing ori(+) and the gene coding for Rep protein. Comparing sequences of the fragments with corresponding sequences of other ss+ plasmids suggested that ori(+) of p1414 belongs to the family of endogenous cryptic B. subtilis plasmids, which form an individual, closely related subgroup in the group of ori(+) sequences of the pC194 type. It was found that the amino acid sequence of a conservative FLTLTV motif located, together with its flanking sequences, at the N ends of Rep proteins encoded by different ss+ plasmids, is similar to those of several transmembrane proteins and signal peptides. These results, together with computer data on predicting the secondary and tertiary structure of the N-terminal domain of the p1414 Rep protein, suggest that the domain can serve as a "membrane anchor" during plasmid replication.

[RecA-independent induction of the new plasmid rAS1 after introduction of a fragment of the cryptic plasmid p1414 into Bacillus subtilis 168 cells]. / RecA-nezavisimaia induktsiia novoi plazmidy pAS1 posle vvedeniia v kletki Bacillus subtilis 168 fragmentov kripticheskoi plazmidy p1414.

Bacillus subtilis 168 was transformed with fragments from the minireplicon of the cryptic plasmid p1414; these fragments were ligated into the cat gene of plasmid pC194. As a result, the 4.6 kb plasmid pAS1 appeared with a low frequency. The plasmid was homologous to the chromosomal DNA of B. subtilis 168, but had no homology with p1414. Plasmid pAS1 had extensive homology (3.2 kb) with plasmid pUB110 and its restriction map in this region of homology correlated well with the restriction map of pUB110. Plasmid pAS1 occurred both in rec+ and recA- cells. We suppose that pAS1 was generated because of the illegitimate recombination between p1414 and the replicon pUB110 incorporated in the chromosome of B. subtilis 168, and the resulting substitution of marker KmR of pUB110 for marker CmR of pC194.

[Plasmids from bacilli related to BAcillus subtilis]. / Plazmidy batsill, rodstvennykh Bacillus subtilis.

The basic structural and functional properties of natural bacilli plasmids are analyzed in this review. Bacilli plasmids are mostly cryptic, but some are found to have selective markers. Small plasmids replicate by rolling-circle mechanism, however, the replication of large plasmids is likely to occur by the theta-mechanism. Plasmid structures involved in replication are analyzed. The bacilli plasmids are stable. They are promising material for vector construction.

[Production of an diagnostic erythrocyte agent from Pseudomonas aeruginosa exotoxin A]. / Poluchenie éritrotsitarnogo diagnostikuma iz ékzotoksina A Pseudomonas aeruginosa.

The sensitization of formolized sheep red blood cells with exotoxin A by means of chromium chloride or glutaraldehyde is more effective with respect to their sensitivity in the passive hemagglutination test than loading by means of amidol, tannin and rivanol. The use of chromium chloride decreases the consumption of exotoxin A 2, 8, 16 and 16 times in comparison with the use of amidol, tannin, rivanol or glutaraldehyde respectively. The high specificity of erythrocyte diagnosticum obtained from exotoxin A by means of chromium chloride is indicated in the study of hyperimmune sera to 22 different antigens of enteric bacteria and staphylococci in the passive hemagglutination test and to 10 different enterobacterial and staphylococcal antigens in the antibody neutralization test.