ACT_SITE 172; /note="Nucleophile"; /evidence="ECO:0000269|PubMed:10358049"; ACT_SITE 343; /note="Charge relay system"; /evidence="ECO:0000269|PubMed:10358049"; ACT_SITE 372; /note="Charge relay system"; /evidence="ECO:0000269|PubMed:10358049"