Proposed scheme of anaerobic metabolism of indoleacetate. Gene products of the A. aromaticum iaa gene cluster are indicated as proposed to catalyze the respective steps, as follows: step I, IAA; step II, 2-oxoindoleacetate, enol form; step III, 2-oxoindoleacetate, keto form; step IV, (2-aminophenyl)succinate; step V, 2(2′-aminophenyl)succinyl-CoA; step VI, 2-aminobenzylmalonyl-CoA.