Bacterial toxin formed by Pseudomonas syringae pv. phaseolicola, the causal agent of halo blight in beans, consisting of the tripeptide ornithine, alanine, and homoarginine and an inorganic group (N-sulfodiaminophosphinyl) attached to the N-5 amino group of orthinine which acts as an inhibitor of ornthine carbamoyltransferase, blocking arginine biosynthesis.