title: Ecori DNA methylase activity is eliminated upon histidine residue modification.
abstract: 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.
authors: Chemistry Department, University of California, Santa Barbara 93106.
authors: E A
authors: EA
authors: Everett
authors: N O
authors: NO
authors: Reich
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D006639:Histidine / Q000378:metabolism*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000037:antagonists & inhibitors*
chemical_list: D006639:Histidine; C020098:DNA modification methylase EcoRI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D004047:Diethyl Pyrocarbonate