Pyridoxal Dependent Decarboxylase Domain Containing Protein 1 (PDXDC1)

PDXDC1 is a pyridoxal dependent decarboxylase belonging to the decarboxylase group II family. Pyridoxal 5-phosphate is a coenzyme for a number of enzymes which catalyse reactions at C^a of amino acid substrates including transaminases, decarboxylases and serine hydroxymethyltransferase. Aspartate aminotransferase, and the results of stereochemical and mechanistic studies for decarboxylases and serine hydroxymethyltransferase, an active-site structure for the decarboxylase group is constructed. The structure of the active-site is further refined through active-site pyridoxyllysine peptide sequence comparison and a 3-D catalytic mechanism for the L-a-amino acid decarboxylases is proposed. The chemistry of serine hydroxymethyltransferase is re-examined in the light of the proposed decarboxylase mechanism.