Chlorophyllide-a oxygenase

Chlorophyllide-a oxygenase
Identifiers
EC no.	1.14.13.122
CAS no.	216503-73-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

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⁺${\displaystyle \rightleftharpoons }$ 7-hydroxychlorophyllide a + H₂O + NADP⁺

(2) 7-hydroxychlorophyllide a + O₂ + NADPH + H⁺${\displaystyle \rightleftharpoons }$ 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

• Biosynthesis of chlorophylls

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.

External links

• Chlorophyllide-a+oxygenase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)