Identification of an RNA-protein complex involved in chloroplast group II intron trans-splicing in Chlamydomonas reinhardtii.
In Chlamydomonas reinhardtii, the psaA mRNA is assembled by a process involving trans-splicing of separate transcripts, encoded at three separate loci of the chloroplast genome. At least 14 nuclear loci and one chloroplast gene, tscA, are needed for this process. We have cloned Raa3, the first nuclear gene implicated in the splicing of intron 1. The predicted sequence of Raa3 consists of 1783 amino acids and shares a small region of homology with pyridoxamine 5'-phosphate oxidases. Raa3 is present in the soluble fraction of the chloroplast and is part of a large 1700 kDa complex, which also contains tscA RNA and the first psaA exon transcript. These partners, in association with other factors, form a chloroplast RNP particle that is required for the splicing of the first intron of psaA and which may be the counterpart of eukaryotic snRNPs involved in nuclear splicing.
Rivier
C
C
Departments of Molecular Biology and Plant Biology, University of Geneva, 30, Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
Goldschmidt-Clermont
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M
Rochaix
J D
JD
D020418:Algal Proteins / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016825:Chlamydomonas reinhardtii / Q000235:genetics / Q000378:metabolism; D060365:Chloroplast Proteins; D002736:Chloroplasts / Q000378:metabolism*; D003001:Cloning, Molecular; D018744:DNA, Plant; D005091:Exons; D017343:Genes, Plant; D007438:Introns; D045342:Light-Harvesting Protein Complexes; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045331:Photosystem I Protein Complex; D010940:Plant Proteins / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics; D018749:RNA, Plant; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D020040:Trans-Splicing
D020418:Algal Proteins; D060365:Chloroplast Proteins; D018744:DNA, Plant; D045342:Light-Harvesting Protein Complexes; D009687:Nuclear Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D010940:Plant Proteins; D015800:Protozoan Proteins; D018749:RNA, Plant; C093455:tscA protein, Chlamydomonas