9AUA

PLP-dependent BesB holoenzyme

9AUA の概要

• エントリーDOI: 10.2210/pdb9aua/pdb
• 関連するPDBエントリー: 9AUB
• 分子名称: BesB, 1,2-ETHANEDIOL, ACETATE ION, ... (6 entities in total)
• 機能のキーワード: pyridoxal 5'-phosphate, alkyne, biosynthetic protein
• 由来する生物種: Streptomyces achromogenes subsp. achromogenes
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 58093.75

構造登録者

Hedges, J.B.,Ryan, K.S. (登録日: 2024-02-28, 公開日: 2025-07-02, 最終更新日: 2026-01-07)

主引用文献

Hedges, J.B.,Marchand, J.A.,Calvo-Tusell, C.,Wei, Z.W.,Millar, D.C.,Garcia-Borras, M.,Chang, M.C.Y.,Ryan, K.S.
Terminal alkyne formation by a pyridoxal phosphate-dependent enzyme.
Nat.Chem.Biol., 22:77-86, 2026

PubMed Abstract: Terminal alkyne-containing natural products can undergo the bio-orthogonal 'click' reaction of Cu(I)-catalyzed azide-alkyne cycloaddition. Recently, an enzymatic mechanism for terminal alkyne formation was discovered in the biosynthesis of L-β-ethynylserine where the pyridoxal phosphate-dependent enzyme BesB forms a rare terminal alkyne-containing amino acid, L-propargylglycine, from a vinyl halide precursor, 4-chloro-L-allylglycine. Here we present the 1.3-Å-resolution crystal structure of BesB with detailed mechanistic and computational studies. We demonstrate that BesB can reversibly catalyze the exchange of the halogen in various 4-halo-allyl-L-glycines, implying the existence of an allene intermediate, which we then also observe. Taken together, this work supports a mechanism whereby an allene is formed from deprotonation-driven halogen loss and the terminal alkyne is then formed by isomerization of the allene. Our work further expands our understanding of the catalytic repertoire of pyridoxal phosphate-dependent enzymes and will enable development of metal-free allene-forming and alkyne-forming biocatalysts.

PubMed: 40562852
DOI: 10.1038/s41589-025-01954-9

実験手法

X-RAY DIFFRACTION (1.29 Å)