The pentatricopeptide repeat gene OTP51 with two LAGLIDADG motifs is required for the cis-splicing of plastid ycf3 intron 2 in Arabidopsis thaliana
The Arabidopsis thaliana chloroplast contains 20 group-II introns in its genome, and seven known splicing factors are required for the splicing of overlapping subsets of 19 of them. We describe an additional protein (OTP51) that specifically promotes the splicing of the only group-II intron for which no splicing factor has been described previously. This protein is a pentatricopeptide repeat (PPR) protein containing two LAGLIDADG motifs found in group-I intron maturases in other organisms. Amino acids thought to be important for the homing endonuclease activity of other LAGLIDADG proteins are missing in this protein, but the amino acids described to be important for maturase activity are conserved. OTP51 is absolutely required for the splicing of ycf3 intron 2, and also influences the splicing of several other group-IIa introns. Loss of OTP51 has far-reaching consequences for photosystem-I and photosystem-II assembly, and for the photosynthetic fluorescence characteristics of mutant plants.
Document Type: Research Article
Affiliations: 1: Australian Research Council Centre of Excellence in Plant Energy Biology, Australian National University, Canberra, Canberra 0200 ACT, Australia 2: Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009 WA, Australia 3: Unité Mixte de Recherche en Génomique Végétale (Institut National de la Recherche Agronomique/Centre National de la Recherche Scientifique/Université d’Evry Val d’Essonne), 91057 Evry, France
Publication date: October 1, 2008