Use of the ND evidence code for Gene Ontology (GO) terms
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
PPR motifs of the nucleus-encoded factor, PGR3, function in the selective and distinct steps of chloroplast gene expression in Arabidopsis.
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Founding genetic study; pgr3 alleles with single PPR-motif substitutions separate the cytochrome b6f and NDH phenotypes, all complemented by PGR3.
"Both phenotypes were complemented by the introduction of a single gene, PGR3, encoding a protein containing 27 pentatrico-peptide repeat (PPR) motifs."
PROTON GRADIENT REGULATION 3 recognizes multiple targets with limited similarity and mediates translation and RNA stabilization in plastids.
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Recombinant PGR3 binds 5' UTR elements of petL; pgr3-2 alters binding specificity; the C-terminus is needed for translation but not binding.
"suggesting that the C-terminal end of PGR3 is not required for binding to targets but is essential for translation of petL and probably also ndhA."
Protein-mediated protection as the predominant mechanism for defining processed mRNA termini in land plant chloroplasts.
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The PGR3 binding site upstream of petL is represented by an sRNA footprint, consistent with PGR3 protecting the processed petL 5' end from exonucleases.
"the binding site of PGR3, a PPR protein that stabilizes the petL 5′-terminus in Arabidopsis (14,29), is represented by an sRNA in these same datasets"
Mutagenesis of individual pentatricopeptide repeat motifs affects RNA binding activity and reveals functional partitioning of Arabidopsis PROTON gradient regulation3.
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The 16 N-terminal PPRs suffice for RNA stabilization via sequence-specific binding; the 11 C-terminal motifs are required for translational activation.
"we showed that the 16 N-terminal PPRs were sufficient for function (1) via sequence-specific RNA binding, whereas the 11 C-terminal motifs were essential for functions (2) and (3) by activating translation."
Unexpected functional versatility of the pentatricopeptide repeat proteins PGR3, PPR5 and PPR10.
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PGR3 binds the rpl14-rps8 intercistronic region, stabilizes a processed 3' end and stimulates rps8 translation; it does not activate ndhA translation.
"In addition, our results show that PGR3 does not activate ndhA translation, as had previously been suggested."
Discovering the RNA-Binding Proteome of Plant Leaves with an Improved RNA Interactome Capture Method.
The Pentatricopeptide Repeat Protein PGR3 Is Required for the Translation of petL and ndhG by Binding Their 5' UTRs.
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PGR3 binding to the 5' UTRs of petL and ndhG relieves translational repression by the bound RNA segment and facilitates translation.
"The putative PGR3-bound RNA segments per se repress the translation possibly with a strong secondary structure and thereby block ribosomes' access."
The Arabidopsis NOT4A E3 ligase promotes PGR3 expression and regulates chloroplast translation.
UniProt record Q9SZ52 (PP344_ARATH)