Has aminomutase and, to a lesser extent, ammonia-lyase activity. Primarily, catalyzes the rearrangement of L-tyrosine to R-beta-tyrosine, which is incorporated into secondary metabolites called chondramides. The aminomutase activity mainly produces R-beta-tyrosine but also S-beta tyrosine in smaller amounts. Does not accept D-tyrosine, L-histidine or L-phenylalanine as substrates. L-tyrosine = 3-amino-3-(4-hydroxyphenyl)propanoate L-tyrosine = (E)-4-coumarate + NH4(+) Homotetramer; dimer of dimers. Contains an active site 4-methylidene-imidazol-5-one (MIO), which is formed autocatalytically by cyclization and dehydration of residues Ala-Ser-Gly. Chondramides are secondary metabolites with antifungal and cytotoxic activity. They are non-ribosomally produced depsipeptides consisting of a polyketide chain and 3 amino acids (alanine, N-methyltryptophan and beta-tyrosine or alpha-methoxy-beta-tyrosine). Belongs to the TAL/TAM family.