The affinity labeling of amino acids in or about the active center of DNA-dependent DNA polymerase I

The use of an affinity label and an inhibitor that shows relative specificity for one amino acid has led to the identification of two amino acid residues in or near the active center of DNA-dependent DNA polymerase I. [35S]-beta-D-Ribosyl-6-methylthiopurine periodate oxidation product ([35S]MMPR-OP) and [14C]phenylglyoxal ([14C]PG) were used to elucidate the presence of a single lysine and arginine in or about the active center of the enzyme.