title: The yeast La protein is required for the 3' endonucleolytic cleavage that matures tRNA precursors.
abstract: Although the La autoantigen binds to the 3' ends of all nascent polymerase III transcripts, its function in vivo has long been unclear. Although S. cerevisiae cells lacking the La protein homolog Lhp1p are viable, cells containing a mutation that disrupts the anticodon stem of tRNA(Ser)CGA require Lhp1p for growth. We demonstrate that for the wild-type pre-tRNA(Ser)CGA and other pre-tRNAs, Lhp1p is required for the normal endonucleolytic removal of the 3' trailer sequence. In cells lacking Lhp1p, the 3' trailer is removed by exonuclease(s). Although maturation of the mutant pre-tRNA(Ser)CGA requires Lhp1p, introduction of a second mutation that restores base pairing eliminates the requirement. We propose that binding by Lhp1p stabilizes pre-tRNAs in conformations that allow the 3' endonucleolytic cleavage to occur.
authors.affiliation: Department of Cell Biology, and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Yoo
authors.forename: S L
authors.initials: SL
authors.lastname: Wolin
mesh_terms: D001324:Autoantigens / Q000235:genetics / Q000378:metabolism*; D001482:Base Composition; D002455:Cell Division / Q000502:physiology; D004720:Endonucleases / Q000378:metabolism; D005092:Exonucleases / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation / Q000502:physiology; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012362:RNA, Transfer, Ser / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000097585:SS-B Antigen
chemical_list: D001324:Autoantigens; D004720:Endonucleases; D005092:Exonucleases; D005656:Fungal Proteins; D012322:RNA Precursors; D012362:RNA, Transfer, Ser; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000097585:SS-B Antigen; C088396:LHP1 protein, S cerevisiae