Details

Autor(en) / Beteiligte

• Hammani, Kamel
• Takenaka, Mizuki
• Miranda, Rafael
• Barkan, Alice

Titel

A PPR protein in the PLS subfamily stabilizes the 5'-end of processed rpl16 mRNAs in maize chloroplasts

Ist Teil von

• Nucleic acids research, 2016-05, Vol.44 (9), p.4278

Ort / Verlag

England

Erscheinungsjahr

2016

Link zum Volltext

Beschreibungen/Notizen

• Pentatricopeptide repeat (PPR) proteins are a large family of helical-repeat proteins that bind RNA in mitochondria and chloroplasts. Precise RNA targets and functions have been assigned to only a small fraction of the >400 members of the PPR family in plants. We used the amino acid code governing the specificity of RNA binding by PPR repeats to infer candidate-binding sites for the maize protein PPR103 and its ortholog Arabidopsis EMB175. Genetic and biochemical data confirmed a predicted binding site in the chloroplast rpl16 5'UTR to be a site of PPR103 action. This site maps to the 5' end of transcripts that fail to accumulate in ppr103 mutants. A small RNA corresponding to the predicted PPR103 binding site accumulates in a PPR103-dependent fashion, as expected of PPR103's in vivo footprint. Recombinant PPR103 bound specifically to this sequence in vitro These observations imply that PPR103 stabilizes rpl16 mRNA by impeding 5'→3' RNA degradation. Previously described PPR proteins with this type of function consist of canonical PPR motifs. By contrast, PPR103 is a PLS-type protein, an architecture typically associated with proteins that specify sites of RNA editing. However, PPR103 is not required to specify editing sites in chloroplasts.