ACT_SITE 29; /evidence="ECO:0000250"; ACT_SITE 32; /evidence="ECO:0000250"; ACT_SITE 88; /note="Schiff-base intermediate with substrate; via pyruvic acid"; /evidence="ECO:0000269|PubMed:2266128"; ACT_SITE 102; /note="Proton donor; for catalytic activity"; /evidence="ECO:0000250"; ACT_SITE 287; /note="Proton acceptor; for processing activity"; /evidence="ECO:0000250"; ACT_SITE 301; /note="Proton acceptor; for processing activity"; /evidence="ECO:0000250"