Catalyzes the reversible cleavage of D-threonine or D-allothreonine into glycine and acetaldehyde. Can also cleave D-beta-phenylserine, D-beta-hydroxy-alpha-aminovaleric acid, D-beta-3,4-dihydroxyphenylserine and D-beta-3,4-methylenedioxyphenylserine into glycine and the corresponding aldehyde compounds. Inactive towards D-serine, beta-hydroxyaspartate and O-phospho-DL-threonine. D-threonine = acetaldehyde + glycine D-allothreonine = acetaldehyde + glycine Binds 1 pyridoxal phosphate per subunit. Binds 1 Mn(2+) ion per subunit. Can also use Co(2+), Ni(2+) and Mg(2+). Inhibited by the carbonyl reagents hydroxylamine, phenylhydrazine and semicarbazide. Inhibited by the chelating agent EDTA. Inhibited by the sulfhydryl reagent p-chloromercuribenzoic acid, and by sodium cyanide. Inhibited by iodoacetate, Ag(2)SO(4), HgCl(2) and CdCl(2). Competitively inhibited by beta-hydroxyaspartate and O-phospho-DL-threonine. Optimum pH is 8.0-9.0. Stable between pH 7.0 and 8.5. Stable below 55 degrees Celsius. Belongs to the DSD1 family.