Structure and Function of the TREX-2 Complex

The Three prime repair exonuclease 2 (TREX-2) complex functionsFunction as a platform to which many of the components of the nuclear mRNA processingMrna processing machinery bind, facilitating integration of this phase of the gene expressionGene expression pathway, as well as mediating the re-positioning of highly regulated actively transcribing genes (such as GAL1) to nuclear poresNuclear pore (NPCs) to accelerate their activation. In Saccharomyces cerevisiae the TREX-2 complexTrex-2 complex is based on a Sac3 scaffold to which Thp1, Sem1, Cdc31 and two Sus1 chains are bound. A combination of X-ray crystallographyX-ray crystallography and electron microscopy studies have established the structureStructure of two major regions of this complex: the M-region that functionsFunction to bind nucleic acids and the CID region that functionsFunction to link the complex to nuclear poresNuclear pore. These structuresStructure have facilitated the engineering of mutants that have been used to define the contributions made by the TREX-2 complexTrex-2 complex to locating high-expressed genes to nuclear poresNuclear pore and the contributions made to mRNA nuclear export.