[Characterization of the transfer-related tra region of the conjugative plasmid p19 from a Bacillus subtilis soil strain].

The nucleotide sequences of three DNA fragments (total size 30574 bp) of the plasmid p19 from the Bacillus subtilis 19 soil strain have been determined. Thirty open reading frames (ORFs) have been identified in these fragments. oriT of the plasmid has also been identified. As shown by the search for homologs of hypothetical protein products of these ORFs in databases, such homology exists for 18 ORFs. The protein products of nine ORFs can be assumed to have specific functions. Several ORFs were inactivated via insertional mutagenesis, and the conjugation capacity of the mutant plasmids was estimated. According to the data on homology of protein products and the results of ORF inactivation, regions of a total size of about 20 kb from the DNA fragments sequenced by us were inferred to belong to the tra region of p19. As follows from the analysis of the identified ORFs of the p19 tra region, it differs from the earlier described tra regions of other plasmids, irrespective of a certain similarity with the corresponding regions of plasmids of gram-positive bacteria from the genera Bacillus, Clostridium, and Listeria.

[Molecular analysis of some genes from plasmid p19 of the soil strain Bacillus subtilis 19 involved in conjugation].

Two fragments of conjugative plasmid p19 (95 kb) from the soil strain Bacillus subtilis 19 were cloned and sequenced; these fragments carry genes, products of which are indispensable for the conjugative transfer. One of the fragments 4518 bp in size carries five open reading frames and their fragments (ORF1-ORF5). The protein corresponding to ORF4 is homologous to proteins from the family VirD4. Inactivation of ORF4 and ORF1 by insertional mutagenesis caused a three-to-fivefold decrease in the frequency of plasmid p19 conjugative transfer. Another 2932-bp fragment of p19 was shown to possess a rep region homologous to the rep region of plasmid pBS72 from the soil strain B. subtilis 72 and a novel ORF (ORF6); the protein corresponding to this ORF contains the HTH motif typical for DNA-binding proteins.

[The structure of the transposable genetic element ISBsu2 in the cryptic plasmid p1516 from a soil Bacillus subtilis strain and the presence of homologues of this element in the chromosomes of various Bacillus subtilis strains]. / Struktura mobil'nogo geneticheskogo élementa ISBsu2 iz kripticheskoi plazmidy P1516 pochvennogo shtamma Bacillus subtilis i nalichie gomologov étogo élementa v khromosomakh razlichnykh shtammov Bacillus subtilis.

A cryptic plasmid from a soil strain of Bacillus subtilis was found to contain a sequence having features of IS element. Homologous sequences were also found in the chromosome of this strain and in the chromosomes of some other B. subtilis strains.

[The ISBsu2 mobile element is present in a plasmid of a soil strain and in the chromosomes of several other strains of Bacillus subtilis]. / Prisutstvie mobil'nogo geneticheskogo élementa ISBsu2 v plazmide pochvennogo shtamma Bacillus subtilis i v khromosomakh riada shtammov étoi bakterii.

Chromosomes of several Bacillus subtilis strains were shown to contain homologs of the ISBsu2 mobile genetic element, which was earlier revealed in a cryptic plasmid of a soil strain of B. subtilis.

[Simultaneous presence of three cryptic plasmids of various size in a soil strain of Bacillus subtilis]. / Odnovremennoe prisutstvie trekh kripicheskikh plazmid raznoi velichiny v pochvennom shtamme Bacillus subtilis.

The Bacillus subtilis 1387 soil strain, which contains three cryptic plasmids simultaneously, was described. Two small plasmids (6.3 and 8.5 kb) were homologous to each other, and a large plasmid (30 kb) had no homology with them. The plasmids were separately transmitted into cells of the Bac. subtilis 168 strain, and some plasmid characteristics were analyzed.