Institute of Biochemistry, FB08, Justus Liebig University, 35392 Giessen, Germany.
Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, 14476 Potsdam-Golm, Germany.
RNA. 2023 Dec;29(12):1870-1880. doi: 10.1261/rna.079758.123. Epub 2023 Sep 12.
The conserved TREX complex has multiple functions in gene expression such as transcription elongation, 3' end processing, mRNP assembly and nuclear mRNA export as well as the maintenance of genomic stability. In , TREX is composed of the pentameric THO complex, the DEAD-box RNA helicase Sub2, the nuclear mRNA export adaptor Yra1, and the SR-like proteins Gbp2 and Hrb1. Here, we present the structural analysis of the endogenous TREX complex of purified from its native environment. To this end, we used cross-linking mass spectrometry to gain structural information on regions of the complex that are not accessible to classical structural biology techniques. We also used negative-stain electron microscopy to investigate the organization of the cross-linked complex used for XL-MS by comparing our endogenous TREX complex with recently published structural models of recombinant THO-Sub2 complexes. According to our analysis, the endogenous yeast TREX complex preferentially assembles into a dimer.
保守的 TREX 复合物在基因表达中具有多种功能，如转录延伸、3'端加工、mRNP 组装和核 mRNA 输出以及基因组稳定性的维持。在酵母中，TREX 由五聚体 THO 复合物、DEAD 盒 RNA 解旋酶 Sub2、核 mRNA 输出接头 Yra1 以及 SR 样蛋白 Gbp2 和 Hrb1 组成。在这里，我们展示了从其天然环境中纯化的内源性 TREX 复合物的结构分析。为此，我们使用交联质谱法获得了无法通过经典结构生物学技术获得的复合物区域的结构信息。我们还使用负染电子显微镜通过比较我们的内源性 TREX 复合物与最近发表的重组 THO-Sub2 复合物的结构模型，研究用于 XL-MS 的交联复合物的组织。根据我们的分析，内源性酵母 TREX 复合物优先组装成二聚体。
