Ecori DNA methylase activity is eliminated upon histidine residue modification.
The E. coli EcoRI DNA methylase activity is completely eliminated in five minutes upon incubation with the histidine residue specific reagent diethyl pyrocarbonate. In that two moles of N-ethoxyformylimidazole per mole of methylase are detected spectroscopically upon inactivation and activity is not restored by hydroxylamine, it is likely that activity loss is due to double modification of a single histidine residue. This information is critical in determining the enzymatic mechanism, causes of the pH-activity curve, designing protein mutants and interpreting previous structure-function data.
Everett
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EA
Chemistry Department, University of California, Santa Barbara 93106.
Reich
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NO
D055598:Chemical Phenomena; D002621:Chemistry; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D006639:Histidine / Q000378:metabolism*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000037:antagonists & inhibitors*
D006639:Histidine; C020098:DNA modification methylase EcoRI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D004047:Diethyl Pyrocarbonate