ACT_SITE 30; /evidence="ECO:0000250"; ACT_SITE 33; /evidence="ECO:0000250"; ACT_SITE 96; /note="Schiff-base intermediate with substrate; via pyruvic acid"; /evidence="ECO:0000250"; ACT_SITE 110; /note="Proton donor; for catalytic activity"; /evidence="ECO:0000250"; ACT_SITE 254; /note="Proton acceptor; for processing activity"; /evidence="ECO:0000250"; ACT_SITE 267; /note="Proton acceptor; for processing activity"; /evidence="ECO:0000250"