Department of Chemistry & Biochemistry, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada.
Department of Biology, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada.
Nat Commun. 2019 Aug 16;10(1):3698. doi: 10.1038/s41467-019-11627-6.
Phosphonates are rare and unusually bioactive natural products. However, most bacterial phosphonate biosynthetic capacity is dedicated to tailoring cell surfaces with molecules like 2-aminoethylphosphonate (AEP). Although phosphoenolpyruvate mutase (Ppm)-catalyzed installation of C-P bonds is known, subsequent phosphonyl tailoring (Pnt) pathway steps remain enigmatic. Here we identify nucleotidyltransferases in over two-thirds of phosphonate biosynthetic gene clusters, including direct fusions to ~60% of Ppm enzymes. We characterize two putative phosphonyl tailoring cytidylyltransferases (PntCs) that prefer AEP over phosphocholine (P-Cho) - a similar substrate used by the related enzyme LicC, which is a virulence factor in Streptococcus pneumoniae. PntC structural analyses reveal steric discrimination against phosphocholine. These findings highlight nucleotidyl activation as a predominant chemical logic in phosphonate biosynthesis and set the stage for probing diverse phosphonyl tailoring pathways.
膦酸酯是罕见且具有异常生物活性的天然产物。然而，大多数细菌的膦酸盐生物合成能力都致力于用 2-氨基乙基膦酸酯（AEP）等分子来修饰细胞表面。虽然磷酸烯醇丙酮酸变位酶（Ppm）催化的 C-P 键的安装是已知的，但随后的磷酰基修饰（Pnt）途径步骤仍然是神秘的。在这里，我们在超过三分之二的膦酸盐生物合成基因簇中鉴定出核苷酸转移酶，包括与 Ppm 酶的~60%直接融合。我们对两个假定的磷酰基修饰胞苷转移酶（PntC）进行了表征，它们更喜欢 AEP 而不是磷酸胆碱（P-Cho）-这是与相关酶 LicC 相似的底物，LicC 是肺炎链球菌中的一种毒力因子。PntC 的结构分析揭示了对磷酸胆碱的空间位阻排斥。这些发现强调了核苷酸激活作为膦酸盐生物合成中的主要化学逻辑，并为探测不同的磷酰基修饰途径奠定了基础。
