A hypothesis on the identification of the editing enzyme in plant organelles

Edited by Micheal R. Sussman

Received 31 May 2007; received in revised form 20 July 2007; accepted 30 July 2007. published online 13 August 2007.

Abstract

RNA editing in plant organelles is an enigmatic process leading to conversion of cytidines into uridines. Editing specificity is determined by proteins; both those known so far are pentatricopeptide repeat (PPR) proteins. The enzyme catalysing RNA editing in plants is still totally unknown. We propose that the DYW domain found in many higher plant PPR proteins is the missing catalytic domain. This hypothesis is based on two compelling observations: (i) the DYW domain contains invariant residues that match the active site of cytidine deaminases; (ii) the phylogenetic distribution of the DYW domain is strictly correlated with RNA editing.

Keywords: RNA editing, PPR protein, DYW domain, Plant evolution

a URGV, 2 Rue Gaston Crémieux, F-91057 Evry Cedex, France

b ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, Australia

c IZMB, Abt. Molekulare Evolution, Kirschallee 1, D-53115 Bonn, Germany

Corresponding author. Fax: +33 1 60 87 45 10.

PII: S0014-5793(07)00856-3

doi:10.1016/j.febslet.2007.07.075

3 of 41