MilM from mildiomycin biosynthesis is an oxygen-, pyridoxal phosphate-dependent arginine hydroxylase

Mildiomycin, a potent antifungal, is biosynthesized through a complex pathway involving the enzyme MilM. This study reassigns MilM as an oxygen (O2)-, pyridoxal phosphate–dependent hydroxylase that hydroxylates the l-arginine–derived side chain of mildiomycin at the C4 position. This activity is conserved with the homologs MppP from enduracididine biosynthesis and RohP from azomycin biosynthesis. We found MilM effectively hydroxylates ʟ-arginine via both a two- and four-electron oxidation pathway in a O2-dependent manner. We also show the hydroxyl group originates from H2O, and the reaction mechanism transitions through conjugated quinonoid intermediates. The O2-, pyridoxal phosphate–dependent transformation of l-arginine catalyzed by MilM ultimately yields the 5-guanidino-2,4-dihydroxyvalerate side chain of mildiomycin. Recharacterization of this essential step in mildiomycin helps elucidate the full pathway of mildiomycin production.

• Publication year

  2025

• Venue

  Journal of Biological Chemistry

• Publication date

  2025-08-01

• Fields of study

  Biology, Medicine, Chemistry

• Identifiers
  DOI 10.1016/j.jbc.2025.110605PMID 40825506PMCID 12464687
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

• Positive regulation of a LuxR family protein, MilO, in mildiomycin biosynthesis

  2024cited by this paper
• A shared mechanistic pathway for pyridoxal phosphate–dependent arginine oxidases

  2021cited by this paper
• Pyridoxal phosphate-dependent reactions in the biosynthesis of natural products.

  2019cited by this paper
• Pyridoxal-5′-phosphate as an oxygenase cofactor: Discovery of a carboxamide-forming, α-amino acid monooxygenase-decarboxylase

  2018cited by this paper
• Streptomyces wadayamensis MppP is a PLP-Dependent Oxidase, Not an Oxygenase.

  2018cited by this paper
• Snapshots of the catalytic cycle of an O2, pyridoxal phosphate‐dependent hydroxylase

  2018cited by this paper
• Differences in PLP-Dependent Cysteinyl Processing Lead to Diverse S-Functionalization of Lincosamide Antibiotics.

  2016cited by this paper
• A pyridoxal phosphate-dependent enzyme that oxidizes an unactivated carbon-carbon bond.

  2016cited by this paper
• Chemistry and diversity of pyridoxal-5'-phosphate dependent enzymes.

  2015cited by this paper
• Streptomyces wadayamensis MppP Is a Pyridoxal 5'-Phosphate-Dependent L-Arginine α-Deaminase, γ-Hydroxylase in the Enduracididine Biosynthetic Pathway.

  2015cited by this paper
• Structure of the N-glycosidase MilB in complex with hydroxymethyl CMP reveals its Arg23 specifically recognizes the substrate and controls its entry

  2014cited by this paper
• Evidence from 18O feeding studies for hydroxyl group donor in the reaction catalyzed by cytidylate hydroxymethylase MilA

  2013cited by this paper
• Analysis of the Mildiomycin Biosynthesis Gene Cluster in Streptoverticillum remofaciens ZJU5119 and Characterization of MilC, a Hydroxymethyl cytosyl‐glucuronic Acid Synthase

  2012cited by this paper
• A genomic overview of pyridoxal‐phosphate‐dependent enzymes

  2003cited by this paper
• Reaction of dopa decarboxylase with L-aromatic amino acids under aerobic and anaerobic conditions.

  2000cited by this paper
• Reaction of dopa decarboxylase with alpha-methyldopa leads to an oxidative deamination producing 3,4-dihydroxyphenylacetone, an active site directed affinity label.

  1998cited by this paper
• Oxygenase side reactions of acetolactate synthase and other carbanion-forming enzymes.

  1991cited by this paper
• Neurotransmitters and neuromodulators in the basal ganglia.

  1990cited by this paper
• Structure of Mildiomycin D

  1984cited by this paper
• Isolation and characterization of mildiomycin, a new nucleoside antibiotic.

  1978cited by this paper

• No citing papers are available for this paper.