5.4.3.6 evolution MIO-dependent aminomutases belong to a class I lyase-like family, in which the MIO group is formed by condensation and cyclization of backbone residues of an (A, T, or S)-Ser-Gly triad in the active site. The active sites of rice tyrosine aminomutase and Taxus canadensis phenylalanine aminomutase share a high degree of sequence identity, which may in part explain why OsTAM also converts phenylalanine to beta-phenylalanine 747148 5.4.3.6 malfunction rice cultivars that do not produce beta-tyrosine have a chromosome 12 deletion that encompasses TAM1 748914 5.4.3.6 metabolism (R)-beta-tyrosine is incorporated into the chondramides produced by Chondromyces crocatus 703203 5.4.3.6 additional information cryptic stereochemistry of the enzyme mechanism, structure-function relationship, detailed overview 727685 5.4.3.6 additional information hemipteran and lepidopteran herbivores show no negative effects at physiologically relevant beta-tyrosine concentrations 748914 5.4.3.6 additional information homology modeling of wild-type enzyme OsTAM and OsTAM mutant enzymes using the phenylalanine aminomutase structure from Taxus canadensis with PDB ID 3NZ4 as template. The active site of enzyme TAM has a flexible inner loop region 747148 5.4.3.6 additional information residues Y125 and N446 not only play a central role in substrate selectivity but, in part, also set the intrinsic reactivity of OsTAM 747104 5.4.3.6 physiological function MIO (3,5-dihydro-5-methylidene-4H-imidazol-4-one)-dependent aminomutases (AMs) are involved in the the biosynthetic pathways of biologically active, medicinal compounds in plants and microorganisms 747148 5.4.3.6 physiological function tyrosine aminomutase TAM1 is required for beta-tyrosine biosynthesis in Oryza sativa, the tyrosine aminomutase converts the common protein amino acid tyrosine (alpha-tyrosine) into beta-tyrosine. beta-Tyrosine is most prevalent in temperate japonica cultivars. beta-Tyrosine is exuded into hydroponic medium at higher concentrations and may contribute to the allelopathic potential of rice. Pseudomonas syringae growth is inhibited by beta-tyrosine, and seedlings of dicot species are much more sensitive to exogenous beta-tyrosine than rice and other tested monocots 748914