Protein
Magnesium dechelatase SGR1, chloroplastic
Organism
Arabidopsis thaliana
Function
Magnesium chelatase involved in chlorophyll a degradation in the chlorophyll-protein complexes of photosystem I (PSI) and photosystem II (PSII) (PubMed:27604697). Contributes to the degradation of PSI and PSII in the thylakoid membranes (PubMed:27604697). Required to trigger chlorophyll degradation during natural and dark-induced leaf senescence (Probable) (PubMed:17468209). Mediates chlorophyll degradation during embryo degreening (PubMed:24043799, PubMed:28873256). Recombinant SGR1 possesses high dechelating activity against chlorophyll a, very low activity against chlorophyllide a, and no activity against chlorophyll b (PubMed:27604697). Magnesium dechelation of chlorophyll a by SGR1 activates chlorophyll b degradation by inducing the expression of NYC1, an enzyme involved in chlorophyll b degradation (PubMed:29425814).
Similarity
Belongs to the staygreen family.
Sequence
MCSLSAIMLLPTKLKPAYSDKRSNSSSSSSLFFNNRRSKKKNQSIVPVARLFGPAIFESSKLKVLFLGVDEKKHPSTLPRTYTLTHSDITAKLTLAISQSINNSQLQGWANRLYRDEVVAEWKKVKGKMSLHVHCHISGGHFLLDLFAKFRYFIFCKELPVVLKAFVHGDGNLLNNYPELQEALVWVYFHSNVNEFNKVECWGPLWEAVSPDGHKTETLPEARCADECSCCFPTVSSIPWSHSLSNEGVNGYSGTQTEGIATPNPEKL