Function
One of five 2-oxo acid decarboxylases (PDC1, PDC5, PDC6, ARO10, and THI3) involved in amino acid catabolism. The enzyme catalyzes the decarboxylation of amino acids, which, in a first step, have been transaminated to the corresponding 2-oxo acids (alpha-keto-acids). In a third step, the resulting aldehydes are reduced to alcohols, collectively referred to as fusel oils or alcohols. Its preferred substrates are the transaminated amino acids derived from leucine (4-methyl-2-oxopentanoate, also alpha-keto-isocaproate) and isoleucine ((3S)-3-methyl-2-oxopentanoate, also alpha-keto-beta-methylvalerate), whereas transaminated valine, transaminated aromatic amino acids, and pyruvate are no substrates. In analogy to the pyruvate decarboxylases the enzyme may in a side-reaction catalyze condensation (or carboligation) reactions leading to the formation of 2-hydroxy ketone, collectively called acyloins. The enzyme is also positively regulating the thiamine metabolism by a molecular mechanism that may involve thiamine concentration sensing and signal transmission.
Sequence
MNSSYTQRYALPKCIAISDYLFHRLNQLNIHTIFGLSGEFSMPLLDKLYNIPNLRWAGNSNELNAAYAADGYSRLKGLGCLITTFGVGELSAINGVAGSYAEHVGILHIVGMPPTSAQTKQLLLHHTLGNGDFTVFHRIASDVACYTTLIIDSELCADEVDKCIKKAWIEQRPVYMGMPVNQVNLPIESARLNTPLDLQLHKNDPDVEKEVISRILSFIYKSQNPAIIVDACTSRQNLIEETKELCNRLKFPVFVTPMGKGTVNETDPQFGGVFTGSISAPEVREVVDFADFIIVIGCMLSEFSTSTFHFQYKTKNCALLYSTSVKLKNATYPDLSIKLLLQKILANLDESKLSYQPSEQPSMMVPRPYPAGNVLLRQEWVWNEISHWFQPGDIIITETGASAFGVNQTRFPVNTLGISQALWGSVGYTMGACLGAEFAVQEINKDKFPATKHRVILFMGDGAFQLTVQELSTIVKWGLTPYIFVMNNQGYSVDRFLHHRSDASYYDIQPWNYLGLLRVFGCTNYETKKIITVGEFRSMISDPNFATNDKIRMIEIMLPPRDVPQALLDRWVVEKEQSKQVQEENENSSAVNTPTPEFQPLLKKNQVGY