title: Molecular Architecture of SF3b and Structural Consequences of Its Cancer-Related Mutations.
abstract: SF3b is a heptameric protein complex of the U2 small nuclear ribonucleoprotein (snRNP) that is essential for pre-mRNA splicing. Mutations in the largest SF3b subunit, SF3B1/SF3b155, are linked to cancer and lead to alternative branch site (BS) selection. Here we report the crystal structure of a human SF3b core complex, revealing how the distinctive conformation of SF3b155's HEAT domain is maintained by multiple contacts with SF3b130, SF3b10, and SF3b14b. Protein-protein crosslinking enabled the localization of the BS-binding proteins p14 and U2AF65 within SF3b155's HEAT-repeat superhelix, which together with SF3b14b forms a composite RNA-binding platform. SF3b155 residues, the mutation of which leads to cancer, contribute to the tertiary structure of the HEAT superhelix and its surface properties in the proximity of p14 and U2AF65. The molecular architecture of SF3b reveals the spatial organization of cancer-related SF3b155 mutations and advances our understanding of their effects on SF3b structure and function.
authors.affiliation: Research Group Macromolecular Crystallography, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Constantin
authors.initials: C
authors.lastname: Cretu
authors.affiliation: Research Group Macromolecular Crystallography, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Schmitzová
authors.affiliation: Research Group Macromolecular Crystallography, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Max Planck Research Group Nucleic Acid Chemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Almudena
authors.initials: A
authors.lastname: Ponce-Salvatierra
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Olexandr
authors.initials: O
authors.lastname: Dybkov
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Evelina I
authors.initials: EI
authors.lastname: De Laurentiis
authors.affiliation: Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany.
authors.forename: Kundan
authors.initials: K
authors.lastname: Sharma
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Will
authors.affiliation: Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Urlaub
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Lührmann
authors.affiliation: Research Group Macromolecular Crystallography, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany. Electronic address: vladimir.pena@mpibpc.mpg.de.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Pena
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D009036:Moths; D009154:Mutation; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015513:Oncogene Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D000072260:RNA Splicing Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017381:Spliceosomes / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D000072668:Splicing Factor U2AF / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: C401561:CDK2AP2 protein, human; D009363:Neoplasm Proteins; D015513:Oncogene Proteins; D010750:Phosphoproteins; D021122:Protein Subunits; D000072260:RNA Splicing Factors; D011994:Recombinant Proteins; C112491:SF3B1 protein, human; D000072668:Splicing Factor U2AF; C000607494:U2AF2 protein, human
keywords: SF3B1; SF3b; U2AF65; cancer-related mutations; crystal structure; pre-mRNA splicing