斯坦福大学Rhiju Das研究组取得一项新突破。他们揭示了低温电镜显示的天然华丽的RNA复合物。相关论文发表在2025年5月6日出版的《自然》杂志上。

在这里，该研究组报告了三种大型华丽细菌RNA的三维结构，以2.9-3.1的分辨率进行低温电子显微镜研究。巨型、华丽、湖泊和乳酸杆菌衍生（GOLLD）、瘤胃起源、华丽、大型（ROOL）和华丽的大型嗜极细菌（OLE） RNA形成同源寡聚物复合物，其化学量在细胞中的浓度低于预期，这在以前的天然RNA分子中没有先例。OLE RNA形成二聚体复合物，具有跨越两个单体的长同轴管。GOLLD和ROOL形成不同的RNA多聚体纳米笼，直径大于核糖体，除了无序环外是空的。广泛的分子内和分子间A-minor相互作用，接吻环，非互A-A螺旋和其他相互作用稳定了这三种配合物。这些大RNA的序列共变分析揭示了分子间相互作用的进化保守性，支持了大的、华丽的RNA四级结构的生物学重要性，这些结构可以在没有任何蛋白质参与的情况下组装。

研究人员表示，无数的天然RNA家族已被提出，但尚未通过实验证明，它们形成了重要的生物学结构。

附：英文原文

Title: Naturally ornate RNA-only complexes revealed by cryo-EM

Author: Kretsch, Rachael C., Wu, Yuan, Shabalina, Svetlana A., Lee, Hyunbin, Nye, Grace, Koonin, Eugene V., Gao, Alex, Chiu, Wah, Das, Rhiju

Issue&Volume: 2025-05-06

Abstract: Myriad families of natural RNAs have been proposed, but not yet experimentally shown, to form biologically important structures1–4. Here we report three-dimensional structures of three large ornate bacterial RNAs using cryogenic electron microscopy at resolutions of 2.9-3.1 . Without precedent among previously characterized natural RNA molecules, Giant, Ornate, Lake- and Lactobacillales-Derived (GOLLD), Rumen-Originating, Ornate, Large (ROOL), and Ornate Large Extremophilic (OLE) RNAs form homo-oligomeric complexes whose stoichiometries are retained at concentrations lower than expected in the cell. OLE RNA forms a dimeric complex with long co-axial pipes spanning two monomers. Both GOLLD and ROOL form distinct RNA-only multimeric nanocages with diameters larger than the ribosome, empty except for a disordered loop. Extensive intra- and intermolecular A-minor interactions, kissing loops, an unusual A-A helix, and other interactions stabilize the three complexes. Sequence covariation analysis of these large RNAs reveals evolutionary conservation of intermolecular interactions, supporting the biological importance of large, ornate RNA quaternary structures that can assemble without any involvement of proteins.

DOI: 10.1038/s41586-025-09073-0

Source: https://www.nature.com/articles/s41586-025-09073-0