5UBP

TREX2 M-region

Summary for 5UBP

• Entry DOI: 10.2210/pdb5ubp/pdb
• Descriptor: Leucine permease transcriptional regulator, Nuclear mRNA export protein THP1, 26S proteasome complex subunit SEM1, ... (4 entities in total)
• Functional Keywords: trex2 complex; tpr repeats, transcription
• Biological source: Saccharomyces cerevisiae RM11-1a; More
• Cellular location: Nucleus envelope : Q08231
• Total number of polymer chains: 3
• Total formula weight: 119295.10

Authors

Stewart, M.,Gordon, J. (deposition date: 2016-12-21, release date: 2017-04-05, Last modification date: 2024-11-06)

Primary citation

Gordon, J.M.B.,Aibara, S.,Stewart, M.
Structure of the Sac3 RNA-binding M-region in the Saccharomyces cerevisiae TREX-2 complex.
Nucleic Acids Res., 45:5577-5585, 2017

PubMed Abstract: 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.

PubMed: 28334829
DOI: 10.1093/nar/gkx158

Experimental method

X-RAY DIFFRACTION (2.3 Å)