SyrB2 in syringomycin E biosynthesis is a nonheme Fe <sup>II</sup> α-ketoglutarate- and O <sub>2</sub> -dependent halogenase
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Machine scores (provisional)
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- Teacher spread
- 0.234 · how far apart the two teachers sit on this one work
- Validation status
score_only:v0-immature-baseline· verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it
Abstract
The nine-residue lipodepsipeptide syringomycin E, elaborated as a phytotoxin by Pseudomonas syringae pv. syringae B301D contains a 4-Cl-L-Thr-9 moiety where failure to chlorinate results in a 3-fold drop in biological activity. The proteins SyrB1 and SyrB2 encoded by the biosynthetic cluster are shown to act as a substrate and enzyme pair for SyrB2-mediated chlorination of the aminoacyl-S-enzyme L-Thr-S-SyrB1. SyrB2 is a member of the nonheme Fe(II) alpha-ketoglutarate-dependent enzyme superfamily, and requires O2 and alpha-ketoglutarate as well as chloride ion to carry out monochlorination of the -CH3 group of L-Thr-S-SyrB1. Chlorination of L-Thr-S-SyrB1 was validated by thioesterase-mediated release of L-Thr and 4-Cl-L-Thr, N-derivatization as fluorescent isoindoles, and HPLC separation compared with authentic standards. Incubations with L-[14C]Thr and [36Cl-] as well as MS of the released products further validated identification. Enzymatic oxidative halogenation is a previously uncharacterized reaction type for nonheme Fe(II) enzymes and may be the general mode for biosynthetic halogenation of aliphatic carbons of natural products.
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The record
- Venue
- Proceedings of the National Academy of Sciences
- Topic
- Metal-Catalyzed Oxygenation Mechanisms
- Field
- Chemistry
- Canadian institutions
- —
- Funders
- National Institute of General Medical SciencesNatural Sciences and Engineering Research Council of CanadaNational Institutes of HealthHelen Hay Whitney Foundation
- Keywords
- HalogenationChemistryBiosynthesisEnzymeMoietyStereochemistryResidue (chemistry)ThioesteraseDerivatizationBiochemistryOrganic chemistryHigh-performance liquid chromatography
- Has abstract in OpenAlex
- yes