title: Structural and biochemical basis for misfolded RNA recognition by the Ro autoantigen.
abstract: The Ro autoantigen is ring-shaped, binds misfolded noncoding RNAs and is proposed to function in quality control. Here we determine how Ro interacts with misfolded RNAs. Binding of Ro to misfolded precursor (pre)-5S ribosomal RNA requires a single-stranded 3' end and helical elements. As mutating most sequences of the helices and tail results in modest decreases in binding, Ro may be able to associate with a range of RNAs. Ro binds several other RNAs that contain single-stranded tails. A crystal structure of Ro bound to a misfolded pre-5S rRNA fragment reveals that the tail inserts into the cavity, while a helix binds on the surface. Most contacts of Ro with the helix are to the backbone. Mutagenesis reveals that Ro has an extensive RNA-binding surface. We propose that Ro uses this surface to scavenge RNAs that fail to bind their specific RNA-binding proteins.
authors.affiliation: Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Fuchs
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Stein
authors.forename: Chunmei
authors.initials: C
authors.lastname: Fu
authors.forename: Karin M
authors.initials: KM
authors.lastname: Reinisch
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Wolin
mesh_terms: D000818:Animals; D001324:Autoantigens; D001483:Base Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D023282:Nuclease Protection Assays / Q000379:methods; D009690:Nucleic Acid Conformation; D009865:Oocytes / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D026721:RNA 3' End Processing; D012322:RNA Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012341:RNA, Ribosomal, 5S / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D000099207:SS-A Antigen
chemical_list: D001324:Autoantigens; D012322:RNA Precursors; D012341:RNA, Ribosomal, 5S; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D000099207:SS-A Antigen