Structure of pyridoxal 5'-phosphate-bound D-threonine aldolase from Chlamydomonas reinhardtii.

D-Threonine aldolase (DTA) is a pyridoxal-5'-phosphate-dependent enzyme which catalyzes the reversible aldol reaction of glycine with a corresponding aldehyde to yield the D-form ß-hydroxy-α-amino acid. This study produced and investigated the crystal structure of DTA from Chlamydomonas reinhardtii (CrDTA) at 1.85 Šresolution. To our knowledge, this is the first report on the crystal structure of eukaryotic DTA. Compared with the structure of bacterial DTA, CrDTA has a similar arrangement of active-site residues. On the other hand, we speculated that some non-conserved residues alter the affinity for substrates and inhibitors. The structure of CrDTA could provide insights into the structural framework for structure-guided protein engineering studies to modify reaction selectivity.