RESUMO
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.
Assuntos
Elementos de DNA Transponíveis/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/genética , Plasmídeos/genética , Replicon/genética , Conjugação Genética/genética , Fator F/genéticaRESUMO
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.
Assuntos
Cromossomos Bacterianos , Escherichia coli/genética , Fator F/genética , Regulação Bacteriana da Expressão Gênica/genética , Leucina/genética , Treonina/genética , Genes Bacterianos , Ligação Genética , Recombinação GenéticaRESUMO
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.
Assuntos
Conjugação Genética/genética , Escherichia coli/genética , Plasmídeos/genética , Tipagem de Bacteriófagos , Colífagos , Escherichia coli/classificação , Fator F/genética , Fímbrias Bacterianas , SorotipagemRESUMO
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.
Assuntos
Escherichia coli/genética , Fímbrias Bacterianas , Expressão Gênica , Plasmídeos , Colífagos/genética , Genes Bacterianos , Mutação , FenótipoRESUMO
Plasmid transfer genetic regulatory system fin N of F-like plasmid pAP27 have been localized on BamHI-restriction fragment f3 (length 8.7 kb). Plasmid pUC19 Fin-activity have been cleared up and characterized from the point of view of its specificity of action on some plasmid transfer functions.
Assuntos
Fator F/genética , Genoma Bacteriano , Clonagem Molecular/métodos , Conjugação Genética/genética , DNA Bacteriano/análise , DNA Bacteriano/genética , Desoxirribonuclease BamHI/genética , Eletroforese em Gel de Ágar , Escherichia coli/genética , Vetores Genéticos/genética , Mapeamento por RestriçãoRESUMO
F-like plasmids pAP19-1::Tn9, pAP20::Tn9, pAP22-1::Tn1, pAP27 characterized by the presence of unique genetic plasmid transfer regulatory systems in their genomes have been found. These systems were named fin K, fin L, fin M, finN, consequently. They were characterized from the point of view of specificity of their action on F-factor and F-like conjugative function. Dependence of fin N-system expression on host-cell and on the order of plasmid entering into host-cell was shown.
Assuntos
Fator F/genética , Conjugação Genética/genética , Escherichia coli/classificação , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/genética , SorotipagemRESUMO
Molecular cloning of genetic region of F-like plasmid pAP42, coding its surface exclusion system (system Six V) was performed. Restriction and genetic analysis of recombinant plasmids showed that six V locus is situated in Sal I-fragment f5 (4.2 MD) of this plasmid.
Assuntos
Clonagem Molecular/métodos , Fator F/genética , Conjugação Genética/genética , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Escherichia coli/genética , Genoma Bacteriano , Mapeamento por RestriçãoRESUMO
With help of nitrosoguanidine 60 mutants of F-like plasmids pAP18-1 drd::Tn 5 and pAP18-1::Tn 9 were induced which determined resistance of E. coli cells of specific phage MS2. Mutational changes in fin-locus of those plasmids were accompanied by phenotypic reversion Fin(-)-Fin+.
Assuntos
Escherichia coli/genética , Fator F/genética , Genes Bacterianos/genética , Mutação/genética , Conjugação Genética/efeitos dos fármacos , Conjugação Genética/genética , Elementos de DNA Transponíveis/efeitos dos fármacos , Elementos de DNA Transponíveis/genética , Escherichia coli/efeitos dos fármacos , Fator F/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/genética , Genes Bacterianos/efeitos dos fármacos , Mutação/efeitos dos fármacos , Nitrosoguanidinas/farmacologiaRESUMO
The identified basic replicons rep1 and rep2 of plasmid pAP42 belong to different groups of incompatibility (inc FIX and inc FVIII). The replicons are partly incompatibile with other inc F-groups too. The results indicate connection between plasmid incompatibility and their replication.
Assuntos
Plasmídeos , Enzimas de Restrição do DNA , Escherichia coli/enzimologia , Peso Molecular , Replicon , beta-Lactamases/genéticaRESUMO
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.
Assuntos
Fator F/genética , Fímbrias Bacterianas/ultraestrutura , Genes Bacterianos/genética , Plasmídeos/genética , Conjugação Genética , Elementos de DNA Transponíveis/genética , Escherichia coli/genética , Escherichia coli/ultraestrutura , Fímbrias Bacterianas/fisiologia , Regulação Bacteriana da Expressão Gênica/genética , Microscopia EletrônicaRESUMO
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).
Assuntos
Escherichia coli/genética , Fator F , Clonagem Molecular , Conjugação Genética , Elementos de DNA Transponíveis , Eletroforese , Genes Bacterianos/genética , Teste de Complementação Genética , Fenótipo , Mapeamento por RestriçãoRESUMO
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.