Journal of Molecular Evolution

, Volume 67, Issue 3, pp 233–245

High Conservation of a 5′ Element Required for RNA Editing of a C Target in Chloroplast psbE Transcripts


DOI: 10.1007/s00239-008-9101-9

Cite this article as:
Hayes, M.L. & Hanson, M.R. J Mol Evol (2008) 67: 233. doi:10.1007/s00239-008-9101-9


C-to-U editing modifies 30–40 distinct nucleotides within higher-plant chloroplast transcripts. Many C targets are located at the same position in homologous genes from different plants; these either could have emerged independently or could share a common origin. The 5′ sequence GCCGUU, required for editing of C214 in tobacco psbE in vitro, is one of the few identified editing cis-elements. We investigated psbE sequences from many plant species to determine in what lineage(s) editing of psbE C214 emerged and whether the cis-element identified in tobacco is conserved in plants with a C214. The GCCGUU sequence is present at a high frequency in plants that carry a C214 in psbE. However, Sciadopitys verticillata (Pinophyta) edits C214 despite the presence of nucleotide differences compared to the conserved cis-element. The C214 site in psbE genes is represented in members of four branches of spermatophytes but not in gnetophytes, resulting in the parsimonious prediction that editing of psbE C214 was present in the ancestor of spermatophytes. Extracts from chloroplasts from a species that has a difference in the motif and lacks the C target are incapable of editing tobacco psbE C214 substrates, implying that the critical trans-acting protein factors were not retained without a C target. Because noncoding sequences are less constrained than coding regions, we analyzed sequences 5′ to two C editing targets located within coding regions to search for possible editing-related conserved elements. Putative editing cis-elements were uncovered in the 5′ UTRs near editing sites psbL C2 and ndhD C2.


PlastidRNA processingPhylogenypsbEndhDpsbL

Supplementary material

239_2008_9101_MOESM1_ESM.xls (290 kb)
[Editing Sites Present in Three Homologous Chloroplast Genes from a Collection of Diverse Species] (XLS 290 kb)
239_2008_9101_MOESM2_ESM.xls (40 kb)
[Editing Sites Present in Three Homologous Chloroplast Genes from a Collection of Diverse Species] (XLS 40 kb)
239_2008_9101_MOESM3_ESM.pdf (134 kb)
[An alignment of psbE sequences around the editing site in Sciadopitys verticillata and homologous sequences in other members of the Conifer II clade defined by Bowe, Coat, and dePamphilis (2000). The nucleotide at the editing site position is indicated by a character in a larger font. Nucleotides that are different from Araucaria bidwillii are represented by grey characters. The 6 nucleotide motif necessary for editing of a tobacco substrate in vitro is depicted by a black box and is underlined] (PDF 134 kb)

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of Molecular Biology and GeneticsCornell UniversityIthacaUSA