Enediyne Antitumor Antibiotic Maduropeptin Biosynthesis Featuring a C-Methyltransferase That Acts on a CoA-Tethered Aromatic Substrate

Abstract

The enediyne antitumor antibiotic maduropeptin (MDP) is produced by Actinomadura madurae ATCC 39144. The biosynthetic pathway for the 3,6-dimethylsalicylic acid moiety of the MDP chromophore is proposed to be comprised of four enzymes: MdpB, MdpB1, MdpB2, and MdpB3. Based on the previously characterized biosynthesis of the naphthoic acid moiety of neocarzinostatin (NCS), we expected a biosynthetic pathway featuring carboxylic acid activation by the MdpB2 CoA ligase immediately before its coupling to an enediyne core intermediate. Surprisingly, the MDP aromatic acid biosynthetic pathway employs an unusual logic in which MdpB2-catalyzed CoA activation occurs before MdpB1-catalyzed C-methylation, demonstrating that MdpB1 is apparently unique in its ability to C-methylate a CoA-tethered aromatic acid. MdpB2 is a promiscuous CoA ligase capable of activating a variety of salicylic acid analogues, a property that could be potentially exploited to engineer MDP analogues.

Discovery of cahuitamycins as biofilm inhibitors derived from a convergent biosynthetic pathway

“…The result indicated a possible unlinked source involved in providing 6-methylsalicylate starter unit. A BLAST analysis using bacterial 6-MSASs including various putative candidates from other bacterial secondary metabolite gene clusters 45 46 47 48 49 , led to the identification of a single iterative type I PKS gene encoding a 6-MSAS (genetic locus 2; GeneBank accession code KU363801 ) located at least ∼50 kb away from cluster 1 based on our S. gandocaensis draft genome-sequencing data ( Fig. 2a ).…”

Genome Mining of Streptomyces sp. Tü 6176: Characterization of the Nataxazole Biosynthesis Pathway

“…In the phenazine pathway,3 -HAA derives from chorismate by the action of an isochorismatase and an anthranilate synthase. [15] Here we report the identification and characterization of the complete gene clusterf or NATb iosynthesis in Streptomyces sp. [9] In the pyrrolobenzodiazepine sibiromycin biosynthesis pathway,3 -HAA derives from l-tryptophan,w hichi sm odified by the kynurenine pathway through the activity of ak ynurenine 3-monoxygenase, an aryl formamidase, at ryptophan-2,3dioxygenase, and ak ynurenine hydrolase.…”

“…The last step would be analogous, but at ad ifferent positiono ft he aromatic ring, to C-methylation,s teps that take place duringt he biosynthesis of 3-hydroxy-4-methyl-anthranilic acid (the building block of the actinomycin chromophore), [14] or of 3,6-dimethylsalicylic (enediyne maduropeptin). [15] Here we report the identification and characterization of the complete gene clusterf or NATb iosynthesis in Streptomyces sp. Tü 6176.…”

Microbial biosynthesis of the anticoagulant precursor 4-hydroxycoumarin

“…WA46), MdpB2 and SsfL1 (involved in maduropeptin and tetracycline SF2575 biosynthesis in Actinomadura madurae ATCC39144 and Streptomyces sp. SF2575, respectively) [24][25][26] . Besides, some benzoate:CoA ligases also exhibited weak side activity towards salicylate 27,28 .…”