Some reactions with aminoacrylate/iminopropionate as an intermediate (there are many more, for example during metabolism of chloroalanine, trans-sulphuration reactions etc.). The cases of cysteine (Woehl et al., 1996), tryptophan (Lambrecht and Downs, 2013), cysteine desulfurase (Zheng et al., 1994) and serine deaminase (Schnackerz et al., 1979), together with RidA (Lambrecht et al., 2013) are shown.