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OTP70 is a pentatricopeptide repeat protein of the E subgroup involved in splicing of the plastid transcript rpoC1
Author(s) -
ChateignerBoutin AnneLaure,
des FrancsSmall Catherine Colas,
Delannoy Etienne,
Kahlau Sabine,
Tanz Sandra K.,
de Longevialle Andéol Falcon,
Fujii Sota,
Small Ian
Publication year - 2011
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2010.04441.x
Subject(s) - pentatricopeptide repeat , rna editing , rna splicing , biology , intron , genetics , post transcriptional modification , rna , alternative splicing , rna binding protein , computational biology , gene , messenger rna
Summary Over 20 proteins of the pentatricopeptide repeat (PPR) family have been demonstrated to be involved in RNA editing in plant mitochondria and chloroplasts. All of these editing factors contain a so‐called ‘E’ domain that has been shown to be essential for editing to occur. The presumption has been that this domain recruits the (unknown) editing enzyme to the RNA. In this report, we show that not all putative E‐class PPR proteins are directly involved in RNA editing. Disruption of the OTP70 gene leads to a strong defect in splicing of the plastid transcript rpoC1 , leading to a virescent phenotype. The mutant has a chloroplast transcript pattern characteristic of a reduction in plastid‐encoded RNA polymerase activity. The E domain of OTP70 is not required for splicing, and can be deleted or replaced by the E domain from the known editing factor CRR4 without loss of rpoC1 splicing. Furthermore, the E domain of OTP70 is incapable of inducing RNA editing when fused to the RNA binding domain of CRR4. We conclude that the truncated E domain of OTP70 is no longer functional in RNA editing, and that the protein has acquired a new function in promoting RNA splicing.