A pyridoxal-phosphate protein. Some alkyl thiols, cyanide, pyrazole and some other heterocyclic compounds can act as acceptors. Not identical with EC
2.5.1.51 (beta-pyrazolylalanine synthase), EC
2.5.1.52 (L-mimosine synthase) and EC
2.5.1.53 (uracilylalanine synthase).