The enzyme, characterized from the bacteria Streptomyces anulatus and Streptosporangium sibiricum, activates 3-hydroxy-4-methylanthranilate, a precursor of actinomycin antibiotics and the antitumor antibiotic sibiromycin, to an adenylate form, so it can be loaded onto a dedicated aryl-carrier protein.
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Giessen, T.W., Kraas, F.I. and Marahiel, M.A. A four-enzyme pathway for 3,5-dihydroxy-4-methylanthranilic acid formation and incorporation into the antitumor antibiotic sibiromycin. Biochemistry50 (2011) 5680–5692. [PMID: 21612226]