ACT_SITE 2; /note="Schiff-base intermediate with DNA"; /evidence="ECO:0000255|PROSITE-ProRule:PRU00392"; ACT_SITE 3; /note="Proton donor"; /evidence="ECO:0000255|PROSITE-ProRule:PRU00392"; ACT_SITE 51; /note="Proton donor; for beta-elimination activity"; /evidence="ECO:0000255|PROSITE-ProRule:PRU00392"; ACT_SITE 250; /note="Proton donor; for delta-elimination activity"; /evidence="ECO:0000255|PROSITE-ProRule:PRU00392"