研究实现在体外和体内扩大吡咯烷基转移RNA合成酶的底物范围

美国加州大学Schepartz Alanna团队报道了在体外和体内扩大吡咯烷基转移RNA合成酶的底物范围，包括非α-氨基酸。相关研究成果发表在2023年6月1日出版的《自然—化学》。

缺乏接受非L-α-氨基酸的正交氨酰基转移RNA（tRNA）合成酶，是阻碍序列定义的异源寡聚物和生物材料体内翻译的主要瓶颈。

该文中，研究人员报道了吡咯烷基tRNA合成酶（PylRS）和某些PylRS变体接受α-羟基、α-硫代和N-甲酰基-L-α-氨基酸，以及作为聚酮天然产物前体的α-羧酸单体。这些单体在体外被翻译装置容纳和接受，那些具有反应性亲核试剂的分子在体内被结合到蛋白质中。对一种PylRS酶和间取代的2-苄基丙二酸衍生物之间形成的复合物的高分辨率结构分析，揭示了一个识别前手性羧酸盐并适应α-羧基取代基的大尺寸和不同静电的活性位点。

该项工作强调了PylRS衍生的酶α-取代基与蛋白质生成氨基酸的α-胺显著不同的单体酰化tRNA的潜力。这些酶或其衍生物可以与天然或进化的核糖体和/或翻译因子协同作用，产生不同的序列定义的非蛋白质杂聚物。

附：英文原文

Title: Expanding the substrate scope of pyrrolysyl-transfer RNA synthetase enzymes to include non-α-amino acids in vitro and in vivo

Author: Fricke, Riley, Swenson, Cameron V., Roe, Leah Tang, Hamlish, Noah Xue, Shah, Bhavana, Zhang, Zhongqi, Ficaretta, Elise, Ad, Omer, Smaga, Sarah, Gee, Christine L., Chatterjee, Abhishek, Schepartz, Alanna

Issue&Volume: 2023-06-01

Abstract: The absence of orthogonal aminoacyl-transfer RNA (tRNA) synthetases that accept non-L-α-amino acids is a primary bottleneck hindering the in vivo translation of sequence-defined hetero-oligomers and biomaterials. Here we report that pyrrolysyl-tRNA synthetase (PylRS) and certain PylRS variants accept α-hydroxy, α-thio and N-formyl-L-α-amino acids, as well as α-carboxy acid monomers that are precursors to polyketide natural products. These monomers are accommodated and accepted by the translation apparatus in vitro; those with reactive nucleophiles are incorporated into proteins in vivo. High-resolution structural analysis of the complex formed between one PylRS enzyme and a m-substituted 2-benzylmalonic acid derivative revealed an active site that discriminates prochiral carboxylates and accommodates the large size and distinct electrostatics of an α-carboxy substituent. This work emphasizes the potential of PylRS-derived enzymes for acylating tRNA with monomers whose α-substituent diverges substantially from the α-amine of proteinogenic amino acids. These enzymes or derivatives thereof could synergize with natural or evolved ribosomes and/or translation factors to generate diverse sequence-defined non-protein heteropolymers.

DOI: 10.1038/s41557-023-01224-y

Source: https://www.nature.com/articles/s41557-023-01224-y

Nature Chemistry：《自然—化学》，创刊于2009年。隶属于施普林格·自然出版集团，最新IF：24.274 官方网址：https://www.nature.com/nchem/ 投稿链接：https://mts-nchem.nature.com/cgi-bin/main.plex