Table 1.

Conversion of substrates after 1 hour with SttH wild type.

Substrate	Conversion [%]	Product
tryptophan (1)	97±4	1 a
3‐indolepropionic acid (2)	57±1.5	2 a:2 b (9:1)
N‐methyltryptophan (3)	68±3	3 a
kynurenine (4)	79±4	4 a
anthranilamide (5)	43±2	5 a
anthranilic acid (6)	1.1±0.1	6 a
N‐phenylanthranilic acid (7)	20±2	7 a

Red indicates conversion to expected product. Blue indicates conversion to chemically favoured products. Assay conditions shown in Figure 2.