Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
Nucleic Acids Res ; 45(3): 1392-1403, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-28180312

RESUMO

All restriction enzymes examined are phosphodiesterases generating 3΄-OH and 5΄-P ends, but one restriction enzyme (restriction glycosylase) excises unmethylated bases from its recognition sequence. Whether its restriction activity involves endonucleolytic cleavage remains unclear. One report on this enzyme, R.PabI from a hyperthermophile, ascribed the breakage to high temperature while another showed its weak AP lyase activity generates atypical ends. Here, we addressed this issue in mesophiles. We purified R.PabI homologs from Campylobacter coli (R.CcoLI) and Helicobacter pylori (R.HpyAXII) and demonstrated their DNA cleavage, DNA glycosylase and AP lyase activities in vitro at 37°C. The AP lyase activity is more coupled with glycosylase activity in R.CcoLI than in R.PabI. R.CcoLI/R.PabI expression caused restriction of incoming bacteriophage/plasmid DNA and endogenous chromosomal DNA within Escherichia coli at 37°C. The R.PabI-mediated restriction was promoted by AP endonuclease action in vivo or in vitro. These results reveal the role of endonucleolytic DNA cleavage in restriction and yet point to diversity among the endonucleases. The cleaved ends are difficult to repair in vivo, which may indicate their biological significance. These results support generalization of the concept of restriction­modification system to the concept of self-recognizing epigenetic system, which combines any epigenetic labeling and any DNA damaging.


Assuntos
Proteínas de Bactérias/metabolismo , DNA Glicosilases/metabolismo , Enzimas de Restrição do DNA/metabolismo , Proteínas de Bactérias/genética , Campylobacter coli/genética , Campylobacter coli/metabolismo , DNA Glicosilases/genética , Reparo do DNA , Enzimas de Restrição do DNA/genética , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Genoma Bacteriano , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Transcriptoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA