Both an altered DNA structure and cellular proteins are involved in protecting a triplex forming an oligopurine-rich sequence from Dam methylation in E. coli.
Biochem Genet
; 34(5-6): 165-78, 1996 Jun.
Article
en En
| MEDLINE
| ID: mdl-8813050
When the 4-bp Dam recognition sequence was placed between two d(GA)7 tracts, it became severely undermethylated in JM101 Escherichia coli cells compared to other Dam sequences in the same plasmid DNA. This site specific undermethylation was also detected on supercoiled molecules in vitro. Mutational analysis indicated that undermethylation is related to the capacity of the oligopurine tract to adopt the H-DNA conformation. In addition, chemical probing of the cells was consistent with a cellular protein bound to the DNA. Therefore it is likely that the combination of altered DNA conformation and a cellular protein leads to Dam-site protection. We also found that the site-specific undermethylation is detectable in certain E. coli strains only.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Purinas
/
Proteínas Bacterianas
/
ADN Bacteriano
/
Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)
/
Escherichia coli
Idioma:
En
Revista:
Biochem Genet
Año:
1996
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos