Structure of the ForT/PRPP complex uncovers the mechanism of C-C bond formation in C-nucleotide antibiotic biosynthesis
Structure of the ForT/PRPP complex uncovers the mechanism of C-C bond formation in C-nucleotide antibiotic biosynthesis
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DOI：
10.1101/2020.03.26.009662
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发表时间：
2020-03
期刊：
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通讯作者：
Sisi Gao;Ashish Radadiya;Wenbo Li;Huanting Liu;Wen Zhu;V. de Crécy-Lagard;N. Richards;J. Naismith
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文献类型：
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作者：
Sisi Gao;Ashish Radadiya;Wenbo Li;Huanting Liu;Wen Zhu;V. de Crécy-Lagard;N. Richards;J. Naismith
C-C键的形成是有机化学的核心，但已知催化该反应的酶促策略相对较少。ForT酶催化5'-磷酸核糖基-1'-焦磷酸（PRPP）和4-氨基-1H-吡唑-3，5-二羧酸之间的C-C键形成，以制备C-核苷酸5'-磷酸福霉素A的生物合成中的关键中间体;我们现在报告ForT/PRPP复合物的2.5 nm分辨率结构，从而定位活性位点。定点诱变已经鉴定出对于PRPP识别和催化至关重要的那些残基。与GHMP激酶的结构保守性表明，带负电荷的焦磷酸离去基团的稳定是至关重要的催化在ForT。提出了这类新的C-C键形成酶的机制。一类新的酶通过不可逆的CO2和焦磷酸盐的产生催化C-C键的形成。
C-C bond formation is at the heart of anabolism and organic chemistry, but relatively few enzymatic strategies for catalyzing this reaction are known. The enzyme ForT catalyzes C-C bond formation between 5’-phosphoribosyl-1’-pyrophosphate (PRPP) and 4-amino-1H-pyrazole-3,5-dicarboxylate to make a key intermediate in the biosynthesis of the C-nucleotide formycin A 5’-phosphate; we now report the 2.5 Å resolution structure of the ForT/PRPP complex and thus locate the active site. Site-directed mutagenesis has identified those residues critical for PRPP recognition and catalysis. Structural conservation with GHMP kinases suggests that stabilization of the negatively charged pyrophosphate leaving group is crucial for catalysis in ForT. A mechanism for this new class of C-C bond forming enzymes is proposed. Entry for the Table of Contents A new class of enzymes catalyse C-C bond formation by irreversible CO2 and pyrophosphate production.