Cloned (Comment) | Organism |
---|---|
gene PPO1, recombinant coexpression of GFP-tagged enzyme PPO1 with HA-tagged MORF2 or MORF9 proteins, all under control of the CaMV 35S promoter, in Arabidopsis thaliana, Coexpression of the N-terminal YFP fusion of PPO1 (YFPNPPO1) and the C-terminal YFP fusion of MORF2, MORF9, or MORF8 (i.e. MORF2-YFPC, MORF9-YFPC, orMORF8-YFPC) reconstituting a functional YFP in chloroplasts | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | construction of a series of Arabidopsis thaliana PPO1 truncations (named D1-8) mutants and interaction analysis of PPO1 mutants with MORF proteins. The N-terminal portion (amino acid residues 113-157, D6) of PPO1 is sufficient for the interaction with MORF2 and MORF9, and the deletion of amino acid residues 136-157 (DELTA22aa) completely abolishes this interaction. indicating that this 22-aa region of PPO1 is critical for the interaction with MORF proteins but not sufficient. MORF2 and MORF9 interact with PPO1 through their N-terminal fragments. Construction of PPO1 with truncations in the FAD binding domain (amino acids 63-69, DELTAFAD) or two substrate binding sites (amino acids 389-395, DELTAS1 and amino acids 403-409, DELTAS2) into ppo1-1. None of the transgenes can rescue the lethal phenotype of the ppo1-1 homozygote, although the transcript level of mutant PPO1 is similar to that of endogenous PPO1 in the wild-type, confirming that the catalytic activity of PPO1 requires efficient FAD and protoporphyrinogen IX binding and indicating that PPO2 expression does not compensate for the loss of PPO1 function | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
chloroplast | - |
Arabidopsis thaliana | 9507 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | Arabidopsis thaliana | enzyme PPO1 directly interacts with proteins MORF2, MORF9, or MORF8, interaction analysis, overview. The RNA editing function of PPO1 depends on its interaction with MORFs | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | P55826 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | enzyme PPO1 directly interacts with proteins MORF2, MORF9, or MORF8, interaction analysis, overview. The RNA editing function of PPO1 depends on its interaction with MORFs | Arabidopsis thaliana | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
PPO1 | - |
Arabidopsis thaliana |
ppo1-1 | - |
Arabidopsis thaliana |
protoporphyrinogen IX oxidase 1 | - |
Arabidopsis thaliana |
Salk_143057 | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | - |
Arabidopsis thaliana |
Organism | Comment | Expression |
---|---|---|
Arabidopsis thaliana | gene PPO1 is induced by light and ubiquitously expressed in plant tissues | up |
General Information | Comment | Organism |
---|---|---|
evolution | because of their importance in catalyzing protoporphyrinogen IX oxidation, the FAD, membrane, and substrate binding domains of PPO1 and PPO2 are largely conserved in species from plants to animals | Arabidopsis thaliana |
malfunction | disruption of protoporphyrinogen IX oxidase 1 (PPO1) causes RNA editing defects in 18 of 34 known plastid RNA target sites, especially those encoded by NADH dehydrogenase-like complex (ndh) genes. Except for the ndhB-746 site, the editing efficiencies of all sites in ndhB, ndhD, ndhF, and ndhG transcripts are reduced to different extents in ppo1 compared with the wild-type, disruption of PPO1 leads to a complete loss of editing of the ndhD-2 site, where ACG is partly edited into the translation start codon AUG in the wild-type. Disruption of PPO1 severely impairs seedling growth, chlorophyll synthesis, and NDH complex accumulation. Loss of FAD or substrate binding of PPO1 does not affect RNA editing. Isozyme PPO2 expression does not compensate for the loss of PPO1 function | Arabidopsis thaliana |
metabolism | enzyme PPO1 is the last enzyme in the common pathway to chlorophyll and heme biosynthesis | Arabidopsis thaliana |
physiological function | the role for PPO1 does not only involve tetrapyrrole biosynthesis but also distinct regulation of plastid RNA editing in higher plants. PPO1 interacts with plastid-localized MORF proteins, which in turn, additionally interact with two PPR proteins, chlororespiratory reduction 28 (CRR28) and organelle transcript processing 82 (OTP82), and a DYW domain-containing protein, DYW1. The interaction with MORFs is critical for the RNA editing function of PPO1. The catalytic activity of PPO1 requires efficient FAD and protoporphyrinogen IX binding | Arabidopsis thaliana |