6ff4

human Bact spliceosome core structurehuman Bact spliceosome core structure

6ff4, resolution 3.40Å Show:Asymmetric Unit Biological Assembly Structural highlights 6ff4 is a 10 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.4Å Ligands: Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SNW1_HUMAN Involved in transcriptional regulation. Modulates TGF-beta-mediated transcription via association with SMAD proteins, MYOD1-mediated transcription via association with PABPN1, RB1-mediated transcriptional repression, and retinoid-X receptor (RXR)- and vitamin D receptor (VDR)-dependent gene transcription in a cell line-specific manner probably involving coactivators NCOA1 and GRIP1. Is involved in NOTCH1-mediated transcriptional activation. Binds to multimerized forms of Notch intracellular domain (NICD) and is proposed to recruit transcriptional coactivators such as MAML1 to form an intermediate preactivation complex which associates with DNA-bound CBF-1/RBPJ to form a transcriptional activation complex by releasing SNW1 and redundant NOTCH1 NICD. Proposed to be involved in transcriptional activation by EBV EBNA2 of CBF-1/RBPJ-repressed promoters. Is recruited by HIV-1 Tat to Tat:P-TEFb:TAR RNA complexes and is involved in Tat transcription by recruitment of MYC, MEN1 and TRRAP to the HIV promoter. Functions as a splicing factor in pre-mRNA splicing. Is required in the specific splicing of CDKN1A pre-mRNA; the function probably involves the recruitment of U2AF2 to the mRNA. Is proposed to recruit PPIL1 to the spliceosome. May be involved in cyclin-D1/CCND1 mRNA stability through the SNARP complex which associates with both the 3'end of the CCND1 gene and its mRNA. Publication Abstract from PubMed The spliceosome is a highly dynamic macromolecular complex that precisely excises introns from pre-mRNA. Here we report the cryo-EM 3D structure of the human B(act) spliceosome at 3.4 A resolution. In the B(act) state, the spliceosome is activated but not catalytically primed, so that it is functionally blocked prior to the first catalytic step of splicing. The spliceosomal core is similar to the yeast B(act) spliceosome; important differences include the presence of the RNA helicase aquarius and peptidyl prolyl isomerases. To examine the overall dynamic behavior of the purified spliceosome, we developed a principal component analysis-based approach. Calculating the energy landscape revealed eight major conformational states, which we refined to higher resolution. Conformational differences of the highly flexible structural components between these eight states reveal how spliceosomal components contribute to the assembly of the spliceosome, allowing it to generate a dynamic interaction network required for its subsequent catalytic activation. Structure and Conformational Dynamics of the Human Spliceosomal B(act) Complex.,Haselbach D, Komarov I, Agafonov DE, Hartmuth K, Graf B, Dybkov O, Urlaub H, Kastner B, Luhrmann R, Stark H Cell. 2018 Jan 25;172(3):454-464.e11. doi: 10.1016/j.cell.2018.01.010. Epub 2018 , Jan 17. PMID:29361316 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Pre-mRNA splicing factors 3D structures