[Identification and characteristics of new systems of genetic plasmid transfer regulation].
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Escherichia coli↗
Biomedical subjects
V P Shchipkov
Publications and source records attributed to V P Shchipkov.
[Specificity of the chromosomal segment of E. coli K-12 in expression regulation of the inhibition systems of the Flac plasmid transfer].
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Chromosomes, Bacterial↗
[Genetic regulation of plasmid transfer].
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DNA Transposable Elements↗
[Molecular cloning of determinants of surface inclusions of the F-like plasmid pAP22-2].
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Bacteriophage lambda↗
[Interaction of the system inhibiting the genetic transfer of types finU and finV in polyplasmid complexes of Escherichia coli K-12 cells].
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Escherichia coli↗
[Features of expression of the genetic region of plasmid pAP42, controlling the synthesis of "sex" pili and surface exclusion system in various E. coli cells].
The results of investigation of serologically--typed and nontyped E. coli cells carrying F-like derepressed plasmid pAP42 testified to the influence of genome of some bacterial hosts on the expression of plasmid genetic region determining "sex" (plasmid--specific) pili synthesis and surface exclusion system (Sfx--system). Similar changes in bacterial cells phenotype can also result from the mutational changes of this plasmid.
Coliphages↗
[The genetic regulation of the conjugative properties of plasmid complex pAP18 in E. coli cells].
Natural plasmid complex pAP18 discovered in E. coli cells consists of F-like plasmid pAP18-1 (Tc, ColV) and N-like plasmid pAP18-2 (Sm) which differ in their genetic transfer. Plasmid pAP18-1 is able to inhibit transfer of plasmid pAP18-2 but not vice versa. These systems are active both in cells of serologically typed and untypable E. coli strains.
Bacteriophage Typing↗
[The genetic regulatory systems of cointegrative plasmid transfer in E. coli K-12 cells].
On the basis of transfer factor pAP42 and nonconjugative plasmids pRSF2124 and pUB781, the cointegrative plasmids pAP42/pRSF2124 and pAP42/pUB781 were constructed. Complex systems of plasmid transfer inhibition (funU and finV) were detected in the structure of cointegrative plasmids.
Conjugation, Genetic↗
[The role of the chromosomal Thr-Leu segment of E. coli K-12 in the expression of the fin-V transfer inhibition system of the F-like plasmid pAP53].
The role E. coli K-12 cell chromosome genetic region (tis-region) in expression of fin V-transfer inhibition system of F-like plasmid pAP53 was shown. The results obtained testify the linkage of tis region and Thr-Leu chromosomal segment.
Chromosomes, Bacterial↗
[Genetic region of incompatibility of the F-like plasmid pAP-18-1].
With help of molecular cloning the genetic region controlling incompatibility of plasmid pAP18-1 (Inc FXI) was localized in EcoR1-fragment f5 (3.6 MD). The genetic region of incompatibility of its derepressed mutant pAP18-1drd (Inc FVII) is situated in EcoR1-fragment f2 (7,2 MD).
Cloning, Molecular↗
[Cloning of genetic transfer region tra and fin gene of conjugative plasmid pAP17-1 in Escherichia coli K-12 cells].
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Cloning, Molecular↗
[Pili determined by the tra genes of F-like plasmids].
The study of structural and functional features of plasmid-specific pili synthetized by E. coli cells under control of 27 F-like plasmids was performed. All the plasmids determined the pili of "flexible" type which were classified into 3 groups on the basis of difference in cell sensitivity to pili-specific phages f1, f2, Q. The possible role of transposons in the variation of pili functional properties was supposed.
Conjugation, Genetic↗
[Genetic organization of transfer region of F-like plasmid pAP18-1].
The results of complementation analysis of nitrosoguanidine-induced mutants of F-like drd-plasmid pAP18-1 (Tc, ColV) testified to the existence of at least 3 tra regions (tra1, tra2, tra3) and regulating locus fin V in the genome of this plasmid. By means of molecular cloning of tra2 region and locus fin V of plasmid pAP18-1drd were located in Sall-fragment f5 (3.9 MD).
Cloning, Molecular↗
[Systems of surface exclusion of F-like plasmids of E. coli and their genetic control].
The F-like plasmids belonging to 5 different Sfx-groups were discovered. The existence of atypical plasmids belonging to different Sfx-groups was shown. The molecular cloning of plasmid DNA fragment (3.9 mD) determining SfxII phenotype was performed.
Cloning, Molecular↗
[Molecular genetic study of the changes in the incompatibility and regulation of the transfer of the F-like pAP18-1 plasmid induced by nitrosoguanidine and the Tn5 and Tn9 transposons].
Relation between induced mutations of plasmid pAP18-1 (Tc, Col) and alterations in it's restriction map was studied. Nitrosoguanidine induced mutations of transfer regulation system and incompatibility of this plasmid related with alteration in the situation of recognition sites for restrictases EcoR1 and Sal1 in map positions 42.2-4.3 and 12.9-17.9 MD. Insertions of transposons Tn5 and Tn9 into the plasmid DNA resulted in a decrease of incompatibility level.
Base Sequence↗
[The transposon content of nonconjugated E. coli plasmids].
The search of nonconjugated plasmids in antibiotic-resistant cells of wild E. coli strains was performed and their transposon maintenance has been studied. The possibility of existence of some different nonconjugated plasmids in one bacterial cells was shown and each plasmid could carry the same transposon. Insertion of one transposon into the conjugated plasmid pAP42 resulted in numerous deletions in the genome of this plasmid.
Conjugation, Genetic↗
[Complementation analysis of derepressed mutants of F-like plasmids of Escherichia coli].
Complementation analysis of a number of conjugative transfer functions was performed in derepressed (drd) mutants of E. coli F-like plasmids. The major part of double plasmid complexes investigated has revealed the formation of complementation transfer inhibitor of Fin V-type, or less frequently--the formation of Fin U-type inhibitor. An additional complementation analysis of drd plasmids defective at Fin V region genes has demonstrated at least three genes (denoted A, B, C) in the structure of this region.
Enzyme Repression↗
[Characteristics of the derepressed mutant of the F-like plasmid pAP18-1 coding for tetracycline resistance in Escherichia coli].
A transfer function derepressed mutant of the F-like plasmid pAP18-1 (Tc, ColV) was induced with the help of N-methyl-N'-nitro-N-nitrozoguanidine. The mutant plasmid pAP18-1drd belongs to the FVII incompatibility group of the F-like plasmids. The plasmid pAP18-1drd is characterized by the loss of the capacity for inhibiting the tra-genes functions of the Flac plasmid and is sensitive to the Tra-function inhibitors of the reference plasmids of the FinV and FinW groups.
Conjugation, Genetic↗