WebX-ray crystal structures are presented of each major step of the assembly-line synthesis by the initiation module of the nonribosomal peptide synthetase (NRPS) LgrA; the structures reveal large conformational changes, demonstrating a requirement for NRPSs to be very dynamic. Non-ribosomal peptides, such as the antibiotic vancomycin and the immunosuppressant cyclosporin A, are peptidic secondary metabolites produced by microorganisms. Non-ribosomal peptide synthetases (NRPSs) are a family of large enzymes that utilize multiple catalytic domains to catalyse sequential steps in the biosynthetic pathway of this family of 'natural products'. Two papers in this issue of Nature present X-ray crystal structures that indicate that NRPSs are substantially more dynamic than previously believed. Andrew Gulick and colleagues studied two holo-non-ribosomal peptide synthetase modules, each revealing a distinct step in the catalytic cycle. Martin Schmeing and colleagues report several structures of LgrA, which is involved in the biosynthesis of the antibiotic gramicidin. Nonribosomal peptide synthetases (NRPSs) are very large proteins that produce small peptide molecules with wide-ranging biological activities, including environmentally friendly chemicals and many widely used therapeutics1. NRPSs are macromolecular machines, with modular assembly-line logic, a complex catalytic cycle, moving parts and many active sites2,3. In addition to the core domains required to link the substrates, they often include specialized tailoring domains, which introduce chemical modifications and allow the product to access a large expanse of chemical space3,4. It is still unknown how the NRPS tailoring domains are structurally accommodated into megaenzymes or how they have adapted to function in nonribosomal peptide synthesis. Here we present a series of crystal structures of the initiation module of an antibiotic-producing NRPS, linear gramicidin synthetase5,6. This module includes the specialized tailoring formylation domain, and states are captured that represent every major step of the assembly-line synthesis in the initiation module. The transitions between conformations are large in scale, with both the peptidyl carrier protein domain and the adenylation subdomain undergoing huge movements to transport substrate between distal active sites. The structures highlight the great versatility of NRPSs, as small domains repurpose and recycle their limited interfaces to interact with their various binding partners. Understanding tailoring domains is important if NRPSs are to be utilized in the production of novel therapeutics.
本文展示了非
核糖体肽合成酶(NRPS)LgrA 起始模块流
水线合成过程中每个主要步骤的 WebX 射线晶体结构;这些结构揭示了巨大的构象变化,证明了 NRPS 需要非常活跃。非
核糖体肽,如抗生素
万古霉素和
免疫抑制剂环孢素 A,是微
生物产生的肽类次级代谢产物。非
核糖体肽合成酶(NRPSs)是一个大型酶家族,利用多个催化结构域催化这一系列 "
天然产物 "
生物合成途径中的连续步骤。本期《自然》杂志刊登的两篇论文展示了 X 射线晶体结构,表明 NRPSs 比人们以前认为的更具活力。Andrew Gulick 及其同事研究了两个全非
核糖体肽合成酶模块,每个模块都揭示了催化循环中的一个独特步骤。Martin Schmeing 及其同事报告了参与抗生素gramicidin
生物合成的 LgrA 的多个结构。非
核糖体肽合成酶(NRPSs)是一种非常大的蛋白质,能产生具有广泛
生物活性的小肽分子,包括环境友好型
化学品和许多广泛使用的治疗药物1。NRPSs 是一种大分子机器,具有模块化流
水线逻辑、复杂的催化循环、活动部件和许多活性位点2,3。除了连接底物所需的核心结构域外,它们通常还包括专门的定制结构域,这些结构域可引入
化学修饰,使产物能够进入广阔的
化学空间3,4。目前还不清楚 NRPS 裁剪结构域是如何在结构上容纳到巨型酶中的,也不清楚它们是如何适应非
核糖体肽合成功能的。在这里,我们展示了一系列抗生素生产 NRPS--线性苎麻素合成酶启动模块的晶体结构5,6。该模块包括专门的裁剪甲酰化结构域,捕捉到的状态代表了启动模块中流
水线合成的每一个主要步骤。构象间的转换规模很大,肽基载体蛋白结构域和
腺苷酸化亚域都在远端活性位点间运输底物时发生了巨大的运动。这些结构突显了 NRPS 的巨大多功能性,因为小结构域会重新利用和循环其有限的界面,以与其不同的结合伙伴相互作用。要想利用 NRPSs 生产新型疗法,了解定制结构域非常重要。