ISSN:
1573-4927
Keywords:
Dam methylation
;
H-DNA
;
triplex
;
footprintingin vivo
;
chemical probes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract When the 4-bp Dam recognition sequence was placed between two d(GA)7 tracts, it became severely undermethylated in JM101Escherichia coli cells compared to other Dam sequences in the same plasmid DNA. This site specific undermethylation was also detected on supercoiled moleculesin 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 certainE. coli strains only.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00553664
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