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Biomedical subjects

T G Mikhaĭlova

Publications and source records attributed to T G Mikhaĭlova.

7 recordsLinked to original sources
PubMed1991

[Cloning and detailed mapping of the fra-ymt region of the Yersinia pestis pFra plasmid].

The genetical libraries of the pFra plasmid of Yersinia pestis genes were obtained by insertion into the PstI, SalGI, EcoRI, XhoI restriction sites of the cosmid vector pHC79. The immunochemical analysis of the recombinant clones has revealed the clones synthesizing the antigen Fl (fraction I) and mouse toxin (Ymt--Yersinia pestis murine toxin). The restriction analysis of the plasmids from antigen synthesizing clones has permitted to construct the detailed physical map of the fra-ymt region of the pFra plasmid the size of 22 kb. The recombinant F1 positive clones of Escherichia coli are able to form at 37 degrees C the capsule-like structure peculiar for Yersinia pestis. The antigen F1 and the mouse toxin were isolated, purified and characterized. The antigen F1 is an 1-2 Md polymer containing a 16 kDa protein subunit. The mouse toxin a 240 kDa protein consisting of 61 kDa subunits. The nucleotide sequence of ymt gene has been defined.

Amino Acid Sequence↗
PubMed1987

[Comparative analysis of the structure of incompatibility plasmids N, P and W].

Evolutionary relationships of the IncN plasmid R15 and other broad host range plasmids (IncN plasmids N3 and R46, IncP plasmids RP4 and R906, IncW plasmids Sa and R388) were studied by Southern blot hybridization technique. The IncN plasmids were shown to harbour homologous determinants for replication and conjugation. No homology was found between the rep and tra genes in R15 and in the IncW and IncP plasmids, respectively. The second rep region of the N3 plasmid is distinctive from the corresponding determinants in the IncN plasmids. Homology was demonstrated for the plasmid genes that mediate restriction and modification in R15 and N3, mercury resistance in R15 and R906, sulfanilamide resistance in R15, N3, R46, Sa, R388, and R906, streptomycin resistance in R15, R46 and Sa. The latter genes are different from the R906 SmR gene. In addition to the three known mobile elements in the plasmid R15, the fourth one (IS46) that is a part of the transposon Tn2353 was identified in this study. Besides, the third copy of this insertion sequence was found in the N3 plasmid.

Base Sequence↗
PubMed1985

[Physical and genetic organization of the plasmid R15].

The conjugative IncN plasmid R15 (SmrSurHgr, 62.3 kb) is cleaved by the hexanucleotide-specific endonucleases BglII, HindIII, EcoRI, BamHI, SmaI, SalI, PstI and XhoI into 9, 9, 6, 5, 4, 4, 4 and 2 fragments, respectively. The restriction sites were located on the physical map of the R15 genome. Distribution of the cleavage sites is strongly asymmetric. 28 of 32 sites for BamHI, EcoRI, HindIII, SalI, SmaI and PstI were located close to or within the sequences of transposable elements Tn2353 and Tn2354. According to the results of analysis of R15::Tn1756 deletion derivatives and recombinant plasmids harboring fragments of R15, the genetic determinants for resistance to Sm, Su and Hg were mapped, as well as the regions necessary for EcoRII restriction--modification and for plasmid replication and conjugation. The features of physical and genetic structures of R15 and other IncN plasmids are discussed.

Attachment Sites, Microbiological↗