EC 6.3.2.40     
Accepted name: cyclopeptine synthase
Reaction: 2 ATP + S-adenosyl-L-methionine + anthranilate + L-phenylalanine = cyclopeptine + 2 AMP + 2 diphosphate + S-adenosyl-L-homocysteine
Glossary: cyclopeptine = (3S)-3-benzyl-4-methyl-3,4-dihydro-1H-1,4-benzodiazepine-2,5-dione
4′-methoxycyclopeptine = (3S)-3-(4-methoxybenzyl)-4-methyl-3,4-dihydro-1H-1,4-benzodiazepine-2,5-dione
Systematic name: S-adenosyl-L-methionine:anthranilate:L-phenylalanine ligase (cyclopeptine-forming)
Comments: Cyclopeptine synthase is the key enzyme of benzodiazepine alkaloid biosynthesis in several fungi species. The enzyme is a non-ribosomal peptide synthase. It is also active with O-methyl-L-tyrosine forming 4′-methoxycyclopeptine.
References:
1.  Lerbs, W. and Luckner, M. Cyclopeptine synthetase activity in surface cultures of Penicillium cyclopium. J. Basic Microbiol. 25 (1985) 387–391. [PMID: 2995633]
2.  Gerlach, M, Schwelle, N., Lerbs, W. and Luckner, M. Enzymatic synthesis of cyclopeptine intermediates in Penicillium cyclopium. Phytochemistry 24 (1985) 1935–1939.
3.  Ishikawa, N., Tanaka, H., Koyama, F., Noguchi, H., Wang, C.C., Hotta, K. and Watanabe, K. Non-heme dioxygenase catalyzes atypical oxidations of 6,7-bicyclic systems to form the 6,6-quinolone core of viridicatin-type fungal alkaloids. Angew. Chem. Int. Ed. Engl. 53 (2014) 12880–12884. [PMID: 25251934]
[EC 6.3.2.40 created 2013]