Knockout of the plastid RNase E leads to defective RNA processing and chloroplast ribosome deficiency.
Plant J
; 64(5): 851-63, 2010 Dec.
Article
en En
| MEDLINE
| ID: mdl-21105931
ABSTRACT
Ribonuclease E (RNase E) represents a key enzyme in bacterial RNA metabolism. It plays multifarious roles in RNA processing and also initiates degradation of mRNA by endonucleolytic cleavage. Plastids (chloroplasts) are derived from formerly free-living bacteria and have largely retained eubacterial gene expression mechanisms. Here we report the functional characterization of a chloroplast RNase E that is encoded by a single-copy nuclear gene in the model plant Arabidopsis thaliana. Analysis of knockout plants revealed that, unlike in bacteria, RNase E is not essential for survival. Absence of RNase E results in multiple defects in chloroplast RNA metabolism. Most importantly, polycistronic precursor transcripts overaccumulate in the knockout plants, while several mature monocistronic mRNAs are strongly reduced, suggesting an important function of RNase E in intercistronic processing of primary transcripts from chloroplast operons. We further show that disturbed maturation of a transcript encoding essential ribosomal proteins results in plastid ribosome deficiency and, therefore, provides a molecular explanation for the observed mutant phenotype.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ribosomas
/
Cloroplastos
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Arabidopsis
/
ARN del Cloroplasto
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Poliadenilación
/
Endorribonucleasas
Idioma:
En
Revista:
Plant J
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2010
Tipo del documento:
Article
País de afiliación:
Alemania