ID 2.7.7.97 DE 3-hydroxy-4-methylanthranilate adenylyltransferase. AN 4-MHA-activating enzyme. AN actinomycin synthase I. CA 3-hydroxy-4-methylanthranilate + ATP + H(+) = 3-hydroxy-4- CA methylanthranilyl-5'-AMP + diphosphate. CC -!- The enzyme, characterized from the bacteria Streptomyces anulatus and CC Streptosporangium sibiricum, activates 3-hydroxy-4- CC methylanthranilate, a precursor of actinomycin antibiotics and the CC antitumor antibiotic sibiromycin, to an adenylate form, so it can be CC loaded onto a dedicated aryl-carrier protein. DR P80435, MHAA_STRAQ ; C0LTL9, MHAA_STRSJ ; //