Assuntos
Bactérias , DNA Bacteriano/genética , DNA Ribossômico/genética , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Técnicas de Tipagem Bacteriana , Federação RussaRESUMO
Integrons are unique natural systems for capturing and spreading the antibiotic resistance genes among Gram-negative bacteria. Gene transfer into small genomes and into plasmids is via site-specific recombination. Integrons act as receptors of antibiotic resistance cassettes. There are known more than 50 cassettes conferring resistance to beta-lactams, aminoglycosides, trimethoprim, chloramphenicol, streptomycin, and other antibiotics. The structure of integrons and of gene cassettes are described and the mechanisms of capture, mobilization, and expression of cassettes considered.
Assuntos
Resistência Microbiana a Medicamentos/genética , Regulação Bacteriana da Expressão Gênica , Bactérias Gram-Negativas/genética , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Óperon , Recombinação GenéticaRESUMO
Site-specific endonuclease R. AspMI was isolated and purified to apparent functional homogeneity from Acinetobacter species (strain M). The enzyme recognizes symmetrical DNA sequence 5'-AGG decreases CCT-3' and cleaves it at the site indicated by the arrow forming blind DNA ends. The endonuclease is an isoschizomer of the StuI endonuclease. Cleavage of the DNA site was inhibited by dcm-methylation. AspMI is approximately equal to 30 kD monomer.
Assuntos
Acinetobacter/enzimologia , Desoxirribonucleases de Sítio Específico do Tipo II/isolamento & purificação , Cromatografia em Gel , Metilação de DNA , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Estabilidade Enzimática , Peso Molecular , Plasmídeos , Mapeamento por Restrição , Especificidade por SubstratoRESUMO
The site-specific endonuclease R . BspIS4I and methylase M . BspIS4I have been isolated and purified to functional purity from the thermophilic strain of Bacillus species IS4. R . BspIS4I recognizes sequence [sequence: see text] on the DNA and cleaves it as indicated by the arrows to form single-stranded 4-nucleotide 5'-protruding termini. The enzyme is an isoschizomer of BbvII. M . BspIS4I is related to adenine-specific methylase.
Assuntos
Bacillus/enzimologia , DNA Metiltransferases Sítio Específica (Adenina-Específica)/isolamento & purificação , Sequência de Bases , Cromatografia por Troca Iônica , DNA Bacteriano/metabolismo , Eletroforese em Gel de Ágar , Dados de Sequência Molecular , DNA Metiltransferases Sítio Específica (Adenina-Específica)/metabolismoAssuntos
Química Clínica , Serviços de Diagnóstico , Serviços de Saúde , Laboratórios , Federação RussaRESUMO
The strain, producing new site-specific endonuclease BcoKI has been found at the screening of the thermophilic bacteria isolated from tobacco. A phenotype characteristic of the strain is given. It has been identified as a new strain Bacillus coagulans. BcoKI, a class-IIS restriction endonuclease has been obtained by three consecutive chromatographies on blue agarose hydroxyapatite and heparin-Sepharose. BcoKI, an isoschizomer of Ksp6321, recognizes the six base non-palindromic sequence 5'CTCTTC3' and cleaves one nucleotide 3' of the 3' cytosine on this strand and four nucleotide 5' of the 5' guanine on the opposite strand to generate a three base 5' overhang.
Assuntos
Bacillus/enzimologia , Desoxirribonucleases de Sítio Específico do Tipo II/biossíntese , Autorradiografia , Sequência de Bases , Cromatografia por Troca Iônica , Desoxirribonucleases de Sítio Específico do Tipo II/isolamento & purificação , Eletroforese em Gel de Ágar , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Especificidade por SubstratoRESUMO
New site-specific endonucleases BspBS31I, BstBS32I, BspIS41, BstTS5I, BspTS514I were isolated from five thermophilic soil bacteria Bacillus sp. BS31, B. stearothermophilus BS32, Bacillus sp. IS4, B. stearothermophilus TS5, Bacillus sp. TS514. The enzymes are isoschizomers of the restriction endonuclease BbvII. Endonuclease BspTS514I was obtained pure from interfering contaminations by two consecutive chromatographies on blue agarose and hydroxyapatite. The enzyme exhibits a maximal activity at 55 degrees C in 10 mM tris-HCl (pH 9.2), 10 mM MgCl2 and 50 mM NaCl.
Assuntos
Bacillus/enzimologia , Enzimas de Restrição do DNA/isolamento & purificação , Sequência de Bases , Cromatografia Líquida , Enzimas de Restrição do DNA/metabolismo , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Especificidade por SubstratoRESUMO
A new restriction endonuclease BstBSI was isolated and purified from the thermophilic soil bacterium Bacillus stearothermophilus BS by the blue sepharose and hydroxyapatite chromatographies. The enzyme is an isoschizomer of SnaI from Sphaerotilus natans C. It recognizes the hexanucleotide GTATAC and cleaves DNA in the center of the sequence. The maximal catalytic activity of the endonuclease is registered in 50 mM tris-HCl (pH 9.0) buffer with the high ionic strength (100 mM NaCl) in the presence of 10 mM MgCl2 at 45 degrees C. Glucosylated DNA of the phage T4 is not cleaved by the enzyme.
Assuntos
Desoxirribonucleases de Sítio Específico do Tipo II/isolamento & purificação , Geobacillus stearothermophilus/enzimologia , Cromatografia em Gel , DNA Viral/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Eletroforese em Gel de Poliacrilamida , Microbiologia do SoloRESUMO
A new restriction endonuclease BspLS2I was isolated from the thermophilic bacterium Bacillus species LS2 and purified by blue sepharose and hydroxyapatite chromatographies. The enzyme is an isoschizomer of SduI from Streptococcus durans. BspLS2I recognizes the sequence 5' G(G/A/T)GC(C/T/A) decreases C 3' on double-stranded DNA and cleaves it is indicated by the arrow to yield sticky-ended DNA fragments. Maximum catalytic activity of endonuclease was found in 10 mM tris-HCl (pH 7.9) in the presence of 15-30 mM MgCl2 at 50 degrees C. The phage T4 glucosylated DNA is not cleaved by the enzyme.
