title: The trans-spliced intron 1 in the psaA gene of the Chlamydomonas chloroplast: a comparative analysis.
abstract: In the secondary structure model that has been proposed for the trans-spliced intron 1 in the Chlamydomonas reinhardtii psaA gene, a third RNA species (tscA RNA) interacts with the 5' and 3' intron parts flanking the exons to reconstitute a composite structure with several features of group-II introns. To test the validity of this model, we undertook the sequencing and modelling of equivalent introns in the psaA gene from other unicellular green algae belonging to the highly diversified genus Chlamydomonas. Our comparative analysis supports the model reported for the C. reinhardtii psaA intron 1, and also indicates that the 5' end of the tscA RNA and the region downstream from the psaA exon 1 cannot be folded into a structure typical of domain I as described for most group-II introns. It is possible that a fourth RNA species, yet to be discovered, provides the parts of domain I which are apparently missing.
authors.affiliation: Département de biochimie, Faculté des sciences et de génie, Université Laval, Québec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Turmel
authors.forename: Y
authors.initials: Y
authors.lastname: Choquet
authors.forename: M
authors.initials: M
authors.lastname: Goldschmidt-Clermont
authors.forename: J D
authors.initials: JD
authors.lastname: Rochaix
authors.forename: C
authors.initials: C
authors.lastname: Otis
authors.forename: C
authors.initials: C
authors.lastname: Lemieux
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002696:Chlamydomonas / Q000235:genetics*; D018742:DNA, Chloroplast / Q000235:genetics*; D007438:Introns; D008958:Models, Molecular; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045331:Photosystem I Protein Complex; D015800:Protozoan Proteins / Q000235:genetics; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D012355:RNA, Transfer, Ile / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D018742:DNA, Chloroplast; C073973:PSI-A protein, Synechococcus; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D015800:Protozoan Proteins; D012333:RNA, Messenger; D012355:RNA, Transfer, Ile; C093455:tscA protein, Chlamydomonas; D015719:Single-Strand Specific DNA and RNA Endonucleases