Involved in phosphonate degradation. (2-aminoethyl)phosphonate + pyruvate = L-alanine + phosphonoacetaldehyde Homodimer. Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. PhnW subfamily. The second enzyme involved in phosphonate degradation (PhnX, EC 3.11.1.1) is not found in this organism. The function of this enzyme is therefore uncertain.