RESUMO
Antibiotic resistance is becoming one of the major crises, among which hydrolysis reaction is widely employed by bacteria to destroy the reactive pharmacophore. Correspondingly, antibiotic producer has canonically co-evolved this approach with the biosynthetic capability for self-resistance. Here we discover a self-defense strategy featuring with reductive inactivation of hemiaminal pharmacophore by short-chain dehydrogenases/reductases (SDRs) NapW and homW, which are integrated with the naphthyridinomycin biosynthetic pathway. We determine the crystal structure of NapW·NADPH complex and propose a catalytic mechanism by molecular dynamics simulation analysis. Additionally, a similar detoxification strategy is identified in the biosynthesis of saframycin A, another member of tetrahydroisoquinoline (THIQ) antibiotics. Remarkably, similar SDRs are widely spread in bacteria and able to inactive other THIQ members including the clinical anticancer drug, ET-743. These findings not only fill in the missing intracellular events of temporal-spatial shielding mode for cryptic self-resistance during THIQs biosynthesis, but also exhibit a sophisticated damage-control in secondary metabolism and general immunity toward this family of antibiotics.
Assuntos
Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Simulação de Dinâmica Molecular , Tetra-Hidroisoquinolinas/metabolismo , Antibacterianos/biossíntese , Antibacterianos/química , Bactérias/genética , Proteínas de Bactérias/genética , Biocatálise , Cromatografia Líquida de Alta Pressão , Resistência Microbiana a Medicamentos/genética , Humanos , Isoquinolinas/química , Isoquinolinas/metabolismo , Espectrometria de Massas/métodos , Estrutura Molecular , NADP/química , NADP/metabolismo , Naftiridinas/química , Naftiridinas/metabolismo , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Tetra-Hidroisoquinolinas/químicaRESUMO
Natural products containing benzoheterocyclic skeletons are widely found in plants and exhibit various pharmacological activities. To address the current limited availability of these compounds, we herein demonstrate the production of benzopyran, furanocoumarins, and pyranocoumarins in Streptomyces xiamenensis by employing prenyltransferases and two substrate-promiscuous enzymes, XimD and XimE. To avoid the degradation in S. xiamenensis, furanocoumarins and pyranocoumarins were also successfully produced in Escherichia coli. The production of linear furanocoumarins (marmesin) and angular pyranocoumarins (decursinol) reached 3.6 and 3.7 mg/L in shake flasks, respectively. To the best of our knowledge, this is the first report of the microbial production of the plant metabolites furanocoumarins and pyranocoumarins. Our study complements the missing link in the biosynthesis of pyranocoumarins by leveraging the catalytic promiscuity of microbial enzymes.