Comella P. auteur aut IRD Pontvianne F. auteur aut IRD Lahmy S. auteur aut IRD Vignols F. auteur aut IRD Barbezier N. auteur aut IRD DeBures A. auteur aut IRD Jobet E. auteur aut IRD Brugidou Christophe auteur aut IRD Echeverria M. auteur aut IRD Saez Vasquez J. auteur aut IRD text journalArticle eng text/pdf born digital access Ribonuclease III (RNaseIII) is responsible for processing and maturation of RNA precursors into functional rRNA, mRNA and other small RNA. In contrast to bacterial and yeast cells, higher eukaryotes contain at least three classes of RNaseIII, including class IV or dicer-like proteins. Here, we describe the functional characterization of AtRTL2, an Arabidopsis thaliana RNaseIII-like protein that belongs to a small family of genes distinct from the dicer family. We demonstrate that AtRTL2 is required for 3external transcribed spacer (ETS) cleavage of the pre-rRNA in vivo. AtRTL2 localizes in the nucleus and cytoplasm, a nuclear export signal (NES) in the N-terminal sequence probably controlling AtRTL2 cellular localization. The modeled 3D structure of the RNaseIII domain of AtRTL2 is similar to the bacterial RNaseIII domain, suggesting a comparable catalytic mechanism. However, unlike bacterial RNaseIII, the AtRTL2 protein forms a highly salt-resistant homodimer that is only disrupted on treatment with DTT. These data indicate that AtRTL2 may use a dimeric mechanism to cleave double-stranded RNA, but unlike bacterial or yeast RNase III proteins, AtRTL2 forms homodimers through formation of disulfide bonds, suggesting that redox conditions may operate to regulate the activity of RNaseIII. specialized 076 36 4 1163-1175 2008 0305-1048 https://www.documentation.ird.fr/hor/fdi:010042530 10.1093/nar/gkm1130 0305-1048 [F B010042530] https://www.documentation.ird.fr/hor/fdi:010042530 https://www.documentation.ird.fr/intranet/publi/2008/04/010042530.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2008-05-06 2017-08-23 fdi:010042530 fre