Methylases
Mostrando 1-12 de 131 artigos, teses e dissertações.
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1. Mutational and acquired carbapenem resistance mechanisms in multidrug resistant Pseudomonas aeruginosa clinical isolates from Recife, Brazil
An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosaisolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes enc
Mem. Inst. Oswaldo Cruz. Publicado em: 15/12/2015
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2. Prevalência de beta-lactamases de amplo espectro e metilases RNAr 16S em isolados clínicos de Pseudomonas aeruginosa multirresistentes recuperados em diferentes hospitais de São Paulo / Prevalence of Extended-spectrum beta-lactamase and 16S rRNA methylases in clinical isolates of multidrug-resistant Pseudomonas aeruginosa recovered from differents hospitals in São Paulo
Introduction and aim: The production of extended-spectrum beta-lactamases (ESBLs) has been restricted to Klebsiella spp. and Escherichia coli, being associated with high rates of resistance, morbidity and mortality. Since genetic determinants for ESBLs (blaESBL genes) are mediated by plasmids, the spread to other medical important species is considered an ep
Publicado em: 2009
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3. Two transfer RNA (1-methylguanine) methylases from yeast.
Two distinct tRNA (m-1G) methylases have been found in the yeast Saccharomyces cerevisiae. They differ in their chromatographic properties on hydroxyapatite, in their response to spermine, and in their site specificity. Only one of the methylases is active against normal tRNA from Escherichia coli.
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4. Sequence motifs characteristic of DNA[cytosine-N4]methyltransferases: similarity to adenine and cytosine-C5 DNA-methylases.
The sequences coding for DNA[cytosine-N4]methyltransferases MvaI (from Micrococcus varians RFL19) and Cfr9I (from Citrobacter freundii RFL9) have been determined. The predicted methylases are proteins of 454 and 300 amino acids, respectively. Primary structure comparison of M.Cfr9I and another m4C-forming methylase, M.Pvu II, revealed extended regions of hom
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5. The mechanism of action of tRNA methylases studied with immobilized tRNAs.
Each of the individual tRNAs immobilized on aminohydroxybutyl-cellulose (ABC) through their oxidized 3'-terminal binds affinitively all methylases present in the enzyme extract irrespective of whether this tRNA will be involved in the following step of methylation or not. These data allow to suggest that (a) the formation of a methylase-tRNA complex and the
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6. The sequence specificity domain of cytosine-C5 methylases.
Prokaryotic DNA[cytosine-C5]methyltransferases (m5C-methylases) share a common architectural arrangement of ten conserved sequence motifs. A series of eleven hybrids have been constructed between the HpaII (recognition sequence: Cm5CGG) and HhaI (recognition sequence: Gm5CGC) DNA-methylases. The hybrids were over-expressed in E.coli and their in vivo methyla
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7. Genetic organization of the KpnI restriction--modification system.
The KpnI restriction-modification (KpnI RM) system was previously cloned and expressed in E. coli. The nucleotide sequences of the KpnI endonuclease (R.KpnI) and methylase (M. KpnI) genes have now been determined. The sequence of the amino acid residues predicted from the endonuclease gene DNA sequence and the sequence of the first 12 NH2-terminal amino acid
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8. REBASE--restriction enzymes and methylases.
REBASE is a comprehensive database of information about restriction enzymes and their associated methylases, including their recognition and cleavage sites and their commercial availability. Information from REBASE is available via monthly electronic mailings as well as via WAIS and anonymous ftp. Specialized files are available that can be used directly by
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9. Purification and characterization of two new modification methylases: MClaI from Caryophanon latum L and MTaqI from Thermus aquaticus YTI.
A method for detecting Type II modification methylases and determining their methylation site by assaying the ability of methylated DNA to be cleaved by heterologous restriction enzymes is described and applied to the isolation of the restriction modification methylases from Thermus thermophilus HB8, Thermus aquaticus YTI and Caryophanon latum L. M.TaqI is s
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10. Characterization and expression of the Escherichia coli Mrr restriction system.
The mrr gene of Escherichia coli K-12 is involved in the acceptance of foreign DNA which is modified. The introduction of plasmids carrying the HincII, HpaI, and TaqI R and M genes is severely restricted in E. coli strains that are Mrr+. A 2-kb EcoRI fragment from the plasmid pBg3 (B. Sain and N. E. Murray, Mol. Gen. Genet. 180:35-46, 1980) was cloned. The r
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11. Inhibitor of Transfer Ribonucleic Acid Methylases in the Differentiating Slime Mold Dictyostelium discoideum
Eight hours after the onset of morphogenesis, an inhibitor of transfer ribonucleic acid methylases appears in differentiating Dictyostelium discoideum. The inhibitor is also present in spores. Fifty per cent of the inhibiting activity is lost upon heating at 100 C for 5 min; it is nondialyzable and sensitive to trypsin.
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12. Cloning and characterization of the HpaII methylase gene.
The HpaII restriction-modification system from Haemophilus parainfluenzae recognizes the DNA sequence CCGG. The gene for the HpaII methylase has been cloned into E. coli and its nucleotide sequence has been determined. The DNA of the clones is fully protected against cleavage by the HpaII restriction enzyme in vitro, indicating that the methylase gene is act