RRC ID 4824
Author Canino G, Bocian E, Barbezier N, Echeverría M, Forner J, Binder S, Marchfelder A.
Title Arabidopsis encodes four tRNase Z enzymes.
Journal Plant Physiol
Abstract Functional transfer RNA (tRNA) molecules are a prerequisite for protein biosynthesis. Several processing steps are required to generate the mature functional tRNA from precursor molecules. Two of the early processing steps involve cleavage at the tRNA 5' end and the tRNA 3' end. While processing at the tRNA 5' end is performed by RNase P, cleavage at the 3' end is catalyzed by the endonuclease tRNase Z. In eukaryotes, tRNase Z enzymes are found in two versions: a short form of about 250 to 300 amino acids and a long form of about 700 to 900 amino acids. All eukaryotic genomes analyzed to date encode at least one long tRNase Z protein. Of those, Arabidopsis (Arabidopsis thaliana) is the only organism that encodes four tRNase Z proteins, two short forms and two long forms. We show here that the four proteins are distributed to different subcellular compartments in the plant cell: the nucleus, the cytoplasm, the mitochondrion, and the chloroplast. One tRNase Z is present only in the cytoplasm, one protein is found exclusively in mitochondria, while the third one has dual locations: nucleus and mitochondria. None of these three tRNase Z proteins is essential. The fourth tRNase Z protein is present in chloroplasts, and deletion of its gene results in an embryo-lethal phenotype. In vitro analysis with the recombinant proteins showed that all four tRNase Z enzymes have tRNA 3' processing activity. In addition, the mitochondrial tRNase Z proteins cleave tRNA-like elements that serve as processing signals in mitochondrial mRNA maturation.
Volume 150(3)
Pages 1494-502
Published 2009-7-1
DOI 10.1104/pp.109.137950
PII pp.109.137950
PMID 19411372
PMC PMC2705019
MeSH Arabidopsis / embryology Arabidopsis / enzymology* Arabidopsis / genetics Arabidopsis Proteins / analysis Arabidopsis Proteins / chemistry Arabidopsis Proteins / genetics* Cell Nucleus / enzymology Chloroplasts / enzymology Cytoplasm / enzymology Endoribonucleases / analysis Endoribonucleases / chemistry Endoribonucleases / genetics* Mitochondria / enzymology Mutation Nucleic Acid Conformation Phenotype Seeds / enzymology Seeds / genetics Seeds / growth & development
IF 6.902
Times Cited 50
Arabidopsis / Cultured plant cells, genes pda10333 pda09488