biostudies-literatureXie YNIAID NIH HHSNHLBI NIH HHSNational Cancer InstituteSchool of Medicine, Vanderbilt UniversityNCI NIH HHSNational Institutes of HealthNIGMS NIH HHS112988https://www.ebi.ac.uk/biostudies/studies/S-EPMC10508174biostudies-literatureUnknown42(8)mRNA in eukaryotic cells is packaged into highly compacted ribonucleoprotein particles (mRNPs) in the nucleus and exported to the cytoplasm for translation. mRNP packaging and export require the evolutionarily conserved transcription-export (TREX) complex. TREX facilitates loading of various RNA-binding proteins on mRNA through the action of its DDX39B subunit. SARNP (Tho1 [transcriptional defect of Hpr1 by overexpression 1] in yeast) is shown to interact with DDX39B and affect mRNA export. The molecular mechanism of how SARNP recognizes DDX39B and functions in mRNP assembly is unclear. Here, we determine the crystal structure of a Tho1/DDX39B/RNA complex, revealing a multivalent interaction mediated by tandem DDX39B interacting motifs in SARNP/Tho1. The high-order complex of SARNP and DDXCell reportsStructural basis for high-order complex of SARNP and DDX39B to facilitate mRNP assembly.PMC10508174T32 CA119925F31 HL162546R01 AI154635R35 GM133743R01 AI125524R35 GM118048T32CA119925Fontoura BMAGazzara MIvey ALXie YZhang KClarke BPLynch KWAngelos AERen YShay JWBhat PMei MHill PSBatten KGao SfalseStructural basis for high-order complex of SARNP and DDX39B to facilitate mRNP assembly.mRNA in eukaryotic cells is packaged into highly compacted ribonucleoprotein particles (mRNPs) in the nucleus and exported to the cytoplasm for translation. mRNP packaging and export require the evolutionarily conserved transcription-export (TREX) complex. TREX facilitates loading of various RNA-binding proteins on mRNA through the action of its DDX39B subunit. SARNP (Tho1 [transcriptional defect of Hpr1 by overexpression 1] in yeast) is shown to interact with DDX39B and affect mRNA export. The molecular mechanism of how SARNP recognizes DDX39B and functions in mRNP assembly is unclear. Here, we determine the crystal structure of a Tho1/DDX39B/RNA complex, revealing a multivalent interaction mediated by tandem DDX39B interacting motifs in SARNP/Tho1. The high-order complex of SARNP and DDX2023-01-01T00:00:00Z2023 Aug2026-05-13T14:36:40.149Z2024-12-04T07:30:50.666ZS-EPMC105081743757886310.1016/j.celrep.2023.112988