Cryo-EM structure of the yeast TREX complex and coordination with the SR-like protein Gbp2

• Published in: eLife 2021-03, Vol.10
• Main Authors: Xie, Yihu, Clarke, Bradley P, Kim, Yong Joon, Ivey, Austin L, Hill, Pate S, Shi, Yi, Ren, Yi
• Format: Article
• Language: English
• Subjects: Adenosine triphosphatase; Biosynthesis; Cryoelectron Microscopy; Cytoplasm; DEAD-box ATPase; Kinases; Mass spectroscopy; mRNA nuclear export; mRNP remodeling; Multigene Family; Proteins; Ren Yi; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; RNA-Binding Proteins - ultrastructure; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae - ultrastructure; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Saccharomyces cerevisiae Proteins - ultrastructure; SR protein; Structural Biology and Molecular Biophysics; Transcription; Yeast
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.65699

The evolutionarily conserved TRanscript-EXport (TREX) complex plays central roles during mRNP (messenger ribonucleoprotein) maturation and export from the nucleus to the cytoplasm. In yeast, TREX is composed of the THO sub-complex (Tho2, Hpr1, Tex1, Mft1, and Thp2), the DEAD box ATPase Sub2, and Yra1. Here we present a 3.7 Å cryo-EM structure of the yeast THO•Sub2 complex. The structure reveals the intimate assembly of THO revolving around its largest subunit Tho2. THO stabilizes a semi-open conformation of the Sub2 ATPase via interactions with Tho2. We show that THO interacts with the serine-arginine (SR)-like protein Gbp2 through both the RS domain and RRM domains of Gbp2. Cross-linking mass spectrometry analysis supports the extensive interactions between THO and Gbp2, further revealing that RRM domains of Gbp2 are in close proximity to the C-terminal domain of Tho2. We propose that THO serves as a landing pad to configure Gbp2 to facilitate its loading onto mRNP.