Chlorophyllide-a oxygenase

Chlorophyllide-a oxygenase
Identifiers
EC no.1.14.13.122
CAS no.216503-73-0
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Chlorophyllide-a oxygenase (EC 1.14.13.122), chlorophyllide a oxygenase, chlorophyll-b synthase, CAO) is an enzyme with systematic name chlorophyllide-a:oxygen 7-oxidoreductase.[1][2][3][4] This enzyme catalyses the following chemical reactions

(1) chlorophyllide a + O2 + NADPH + H+ 7-hydroxychlorophyllide a + H2O + NADP+
(2) 7-hydroxychlorophyllide a + O2 + NADPH + H+ chlorophyllide b + 2 H2O + NADP+
Chlorophyllide a, (R=H) is converted to chlorophyllide b, in which the methyl group show in the green box is oxidised to a formyl group.

This enzyme contains a mononuclear iron centre and is part of the biosynthetic pathway to chlorophylls.[5][6]

See also

References

  1. ^ Espineda CE, Linford AS, Devine D, Brusslan JA (August 1999). "The AtCAO gene, encoding chlorophyll a oxygenase, is required for chlorophyll b synthesis in Arabidopsis thaliana". Proceedings of the National Academy of Sciences of the United States of America. 96 (18): 10507–11. Bibcode:1999PNAS...9610507E. doi:10.1073/pnas.96.18.10507. PMC 17919. PMID 10468639.
  2. ^ Oster U, Tanaka R, Tanaka A, Rüdiger W (February 2000). "Cloning and functional expression of the gene encoding the key enzyme for chlorophyll b biosynthesis (CAO) from Arabidopsis thaliana". The Plant Journal. 21 (3): 305–10. doi:10.1046/j.1365-313x.2000.00672.x. PMID 10758481.
  3. ^ Eggink LL, LoBrutto R, Brune DC, Brusslan J, Yamasato A, Tanaka A, Hoober JK (April 2004). "Synthesis of chlorophyll b: localization of chlorophyllide a oxygenase and discovery of a stable radical in the catalytic subunit". BMC Plant Biology. 4: 5. doi:10.1186/1471-2229-4-5. PMC 406501. PMID 15086960.
  4. ^ Porra RJ, Schäfer W, Cmiel E, Katheder I, Scheer H (January 1994). "The derivation of the formyl-group oxygen of chlorophyll b in higher plants from molecular oxygen. Achievement of high enrichment of the 7-formyl-group oxygen from 18O2 in greening maize leaves" (PDF). European Journal of Biochemistry. 219 (1–2): 671–9. doi:10.1111/j.1432-1033.1994.tb19983.x. PMID 8307032.
  5. ^ Willows, Robert D. (2003). "Biosynthesis of chlorophylls from protoporphyrin IX". Natural Product Reports. 20 (6): 327–341. doi:10.1039/B110549N. PMID 12828371.
  6. ^ Bollivar, David W. (2007). "Recent advances in chlorophyll biosynthesis". Photosynthesis Research. 90 (2): 173–194. doi:10.1007/s11120-006-9076-6. PMID 17370354. S2CID 23808539.