Purification, Crystallization And Preliminary X-ray Diffraction Analysis Of The Nuclear Messenger RNA Export Related Protein

Gene expression in eukaryotes is a multistep process including transcription initiation, elongation, and termination, processing of the mRNA and its packaging into a mature mRNP, and finally export of the mRNP to the cytoplasm, where it is translated by the ribosomes.In eukaryotes most mature RNA must be exported to the cytoplasm from the nucleus. While some RNAs function in the nucleus, many RNAs are transported through the nuclear pores and into the cytosol. Notably this includes all RNA types involved in protein synthesis. Messenger RNA export includes transcription, processing, translocation through NPC, and translation.The conserved TREX complex couples transcription to nuclear mRNA export. The novel protein Swtl (synthetically lethal with TREX) mainly localized in the nucleus, and functions in gene expression in conjunction with the TREX complex. SWT1is an essential transcriptional protein shows endonuclease activity due to its possession of PIN domain. SWTl works together with the factors that function in nuclear mRNP cotranscriptional assembly quality control. It also associates with the NPC through interaction with nuclear basket components Mlp1, Nup60, and Escl. To investigate the structural basis of Swtl transcriptional function, we carried out the preliminary crystallographic study of SWT1from Saccharomyces cerevisiae, by cloning, expression, purification and crystallization. Now, we got a set of3.0A resolution diffraction data for native Swtl crystal but failed to solve its structure by molecule replacement method. Selenomethionine labeled crystal optimization is currently in progress.