ACT_SITE 71; /note="Schiff-base intermediate with substrate; via pyruvic acid"; /evidence="ECO:0000255|HAMAP-Rule:MF_00464"; ACT_SITE 76; /note="Proton acceptor; for processing activity"; /evidence="ECO:0000255|HAMAP-Rule:MF_00464"; ACT_SITE 91; /note="Proton donor; for catalytic activity"; /evidence="ECO:0000255|HAMAP-Rule:MF_00464"