Structure of the Sac3 RNA-binding M-region in the Saccharomyces cerevisiae TREX-2 complex
| Autor: | James M. B. Gordon, Murray Stewart, Shintaro Aibara |
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| Rok vydání: | 2017 |
| Předmět: |
Models
Molecular 0301 basic medicine Saccharomyces cerevisiae Proteins Protein domain Saccharomyces cerevisiae Active Transport Cell Nucleus Biology Crystallography X-Ray Protein Structure Secondary 03 medical and health sciences Protein structure Protein Domains Structural Biology Gene expression Genetics medicine RNA Messenger Gene Cell Nucleus Messenger RNA RNA RNA Fungal biology.organism_classification Cell biology Cell nucleus 030104 developmental biology medicine.anatomical_structure Multiprotein Complexes |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| DOI: | 10.1093/nar/gkx158 |
| Popis: | Transcription-export complex 2 (TREX-2, or THSC) facilitates localization of actively transcribing genes such as GAL1 to the nuclear periphery, contributes to the generation of export-competent mRNPs and influences gene expression through interactions with Mediator. TREX-2 is based on a Sac3 scaffold to which Thp1, Sem1, Cdc31 and Sus1 bind and consists of three modules: the N-region (Sac3∼1-100), which binds mRNA export factor Mex67:Mtr2; the M-region, in which Thp1 and Sem1 bind to Sac3∼100-550; and the CID region in which Cdc31 and two Sus1 chains bind to Sac3∼720-805. Although the M-region of Sac3 was originally thought to encompass residues ∼250-550, we report here the 2.3Å resolution crystal structure of a complex containing Sac3 residues 60–550 that indicates that the TPR-like repeats of the M-region extend to residue 137 and that residues 90–125 form a novel loop that links Sac3 to Thp1. These new structural elements are important for growth and mRNA export in vivo. Although deleting Sac3 residues 1–90 produced a wild-type phenotype, deletion of the loop as well generated growth defects at 37°C, whereas the deletion of residues 1–250 impaired mRNA export and also generated longer lag times when glucose or raffinose was replaced by galactose as the carbon source. |
| Databáze: | OpenAIRE |
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