- Biosynthesis of Mycotoxin Fusaric Acid and Application of a PLP-Dependent Enzyme for Chemoenzymatic Synthesis of Substituted l -Pipecolic Acids
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Fusaric acid (FA) is a well-known mycotoxin that plays an important role in plant pathology. The biosynthetic gene cluster for FA has been identified, but the biosynthetic pathway remains unclarified. Here, we elucidated the biosynthesis of FA, which features a two-enzyme catalytic cascade, a pyridoxal 5′-phosphate (PLP)-dependent enzyme (Fub7), and a flavin mononucleotide (FMN)-dependent oxidase (Fub9) in synthesizing the picolinic acid scaffold. FA biosynthesis also involves an off-line collaboration between a highly reducing polyketide synthase (HRPKS, Fub1) and a nonribosomal peptide synthetase (NRPS)-like carboxylic acid reductase (Fub8) in making an aliphatic α,β-unsaturated aldehyde. By harnessing the stereoselective C-C bond-forming activity of Fub7, we established a chemoenzymatic route for stereoconvergent synthesis of a series of 5-alkyl-, 5,5-dialkyl-, and 5,5,6-trialkyl-l-pipecolic acids of high diastereomeric ratio.
- Hai, Yang,Chen, Mengbin,Huang, Arthur,Tang, Yi
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supporting information
p. 19668 - 19677
(2020/12/01)
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- Coupling bioorthogonal chemistries with artificial metabolism: Intracellular biosynthesis of azidohomoalanine and its incorporation into recombinant proteins
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In this paper, we present a novel, single experiment methodology based on genetic engineering of metabolic pathways for direct intracellular production of non-canonical amino acids from simple precursors, coupled with expanded genetic code. In particular, we engineered the intracellular biosynthesis of L-Azidohomoalanine from O-Acetyl-L-homoserine and NaN3, and achieved its direct incorporation into recombinant target proteins by AUG codon reassignment in a methionine-Auxotroph E. coli strain. In our system, the host's methionine biosynthetic pathway was first diverted towards the production of the desired non-canonical amino acid by exploiting the broad reaction specificity of recombinant pyridoxal phosphate-dependent O-Acetylhomoserine sulfhydrylase from Corynebacterium glutamicum. Then, the expression of the target protein barstar, accompanied with efficient L-Azidohomoalanine incorporation in place of L-methionine, was accomplished. This work stands as proof-of-principle and paves the way for additional work towards intracellular production and site-specific incorporation of biotechnologically relevant non-canonical amino acids directly from common fermentable sources.
- Ma, Ying,Biava, Hernan,Contestabile, Roberto,Budisa, Nediljko,Di Salvo, Martino Luigi
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p. 1004 - 1022
(2014/02/14)
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