Protein: Magnesium-chelatase subunit ChlH, chloroplastic (Mg-chelatase subunit H) (EC 6.6.1.1) (ABA-binding protein) (Mg-protoporphyrin IX chelatase subunit ChlH) (Protein CONDITIONAL CHLORINA) (Protein GENOMES UNCOUPLED 5) (Protein RAPID TRANSPIRATION IN DETACHED LEAVES 1) (Q9FNB0)
Organism: Arabidopsis thaliana (Mouse-ear cress)
Function: Multifunctional protein involved in chlorophyll synthesis, plastid-to-nucleus retrograde signaling and abscisic acid (ABA) perception. In chlorophyll synthesis, catalyzes the insertion of magnesium ion into protoporphyrin IX to yield Mg-protoporphyrin IX. The reaction takes place in two steps, with an ATP-dependent activation followed by an ATP-dependent chelation step. In addition to its function in the Mg-chelatase enzyme, is required for the plastid-to-nucleus retrograde signaling. The plastid-to-nucleus signal plays an important role in the coordinated expression of both nuclear- and chloroplast-localized genes that encode photosynthesis-related proteins. Has a role in mediating ABA signaling in stomatal guard cells and during seed germination. Binds ABA and is a positive regulator of ABA signaling.
Subcellular location: Plastid, chloroplast stroma. Plastid, chloroplast membrane; Peripheral membrane protein; Stromal side. Plastid, chloroplast membrane; Peripheral membrane protein; Cytoplasmic side. Note=Predominantly associated with the chloroplast envelope. Spans the chloroplast envelope and is its N- and C-termini are exposed to the cytosol (PubMed:20543028). {ECO:0000269|PubMed:20543028}.
Interaction partners:
- Magnesium-chelatase subunit ChlI-1, chloroplastic
- Magnesium-chelatase subunit ChlI-2, chloroplastic
- Magnesium protoporphyrin IX methyltransferase, chloroplastic
- Magnesium-chelatase subunit ChlD, chloroplastic
- Protoporphyrinogen oxidase 2, chloroplastic/mitochondrial
- Ferrochelatase-1, chloroplastic/mitochondrial
- Protoporphyrinogen oxidase 1, chloroplastic
- Tetrapyrrole-binding protein, chloroplastic
- Geranylgeranyl diphosphate reductase, chloroplastic
- Magnesium-protoporphyrin IX monomethyl ester [oxidative] cyclase, chloroplastic
Sequence:
MASLVYSPFTLSTSKAEHLSSLTNSTKHSFLRKKHRSTKPAKSFFKVKSAVSGNGLFTQTNPEVRRIVPIKRDNVPTVKIVYVVLEAQYQSSLSEAVQSLNKTSRFASYEVVGYLVEELRDKNTYNNFCEDLKDANIFIGSLIFVEELAIKVKDAVEKERDRMDAVLVFPSMPEVMRLNKLGSFSMSQLGQSKSPFFQLFKRKKQGSAGFADSMLKLVRTLPKVLKYLPSDKAQDARLYILSLQFWLGGSPDNLQNFVKMISGSYVPALKGVKIEYSDPVLFLDTGIWHPLAPTMYDDVKEYWNWYDTRRDTNDSLKRKDATVVGLVLQRSHIVTGDDSHYVAVIMELEARGAKVVPIFAGGLDFSGPVEKYFVDPVSKQPIVNSAVSLTGFALVGGPARQDHPRAIEALKKLDVPYLVAVPLVFQTTEEWLNSTLGLHPIQVALQVALPELDGAMEPIVFAGRDPRTGKSHALHKRVEQLCIRAIRWGELKRKTKAEKKLAITVFSFPPDKGNVGTAAYLNVFASIFSVLRDLKRDGYNVEGLPENAETLIEEIIHDKEAQFSSPNLNVAYKMGVREYQDLTPYANALEENWGKPPGNLNSDGENLLVYGKAYGNVFIGVQPTFGYEGDPMRLLFSKSASPHHGFAAYYSYVEKIFKADAVLHFGTHGSLEFMPGKQVGMSDACFPDSLIGNIPNVYYYAANNPSEATIAKRRSYANTISYLTPPAENAGLYKGLKQLSELISSYQSLKDTGRGPQIVSSIISTAKQCNLDKDVDLPDEGLELSPKDRDSVVGKVYSKIMEIESRLLPCGLHVIGEPPSAMEAVATLVNIAALDRPEDEISALPSILAECVGREIEDVYRGSDKGILSDVELLKEITDASRGAVSAFVEKTTNSKGQVVDVSDKLTSLLGFGINEPWVEYLSNTKFYRANRDKLRTVFGFLGECLKLVVMDNELGSLMQALEGKYVEPGPGGDPIRNPKVLPTGKNIHALDPQAIPTTAAMASAKIVVERLVERQKLENEGKYPETIALVLWGTDNIKTYGESLGQVLWMIGVRPIADTFGRVNRVEPVSLEELGRPRIDVVVNCSGVFRDLFINQMNLLDRAIKMVAELDEPVEQNFVRKHALEQAEALGIDIREAATRVFSNASGSYSANISLAVENSSWNDEKQLQDMYLSRKSFAFDSDAPGAGMAEKKQVFEMALSTAEVTFQNLDSSEISLTDVSHYFDSDPTNLVQSLRKDKKKPSSYIADTTTANAQVRTLSETVRLDARTKLLNPKWYEGMMSSGYEGVREIEKRLSNTVGWSATSGQVDNWVYEEANSTFIQDEEMLNRLMNTNPNSFRKMLQTFLEANGRGYWDTSAENIEKLKELYSQVEDKIEGIDR