Biology:Chlorophyllide-a oxygenase

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Short description: Class of enzymes
Chlorophyllide-a oxygenase
Identifiers
EC number1.14.13.122
CAS number216503-73-0
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum

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+ [math]\displaystyle{ \rightleftharpoons }[/math] 7-hydroxychlorophyllide a + H2O + NADP+
(2) 7-hydroxychlorophyllide a + O2 + NADPH + H+ [math]\displaystyle{ \rightleftharpoons }[/math] 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. "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. August 1999. doi:10.1073/pnas.96.18.10507. PMID 10468639. Bibcode1999PNAS...9610507E. 
  2. "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. February 2000. doi:10.1046/j.1365-313x.2000.00672.x. PMID 10758481. 
  3. "Synthesis of chlorophyll b: localization of chlorophyllide a oxygenase and discovery of a stable radical in the catalytic subunit". BMC Plant Biology 4: 5. April 2004. doi:10.1186/1471-2229-4-5. PMID 15086960. 
  4. "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". European Journal of Biochemistry 219 (1–2): 671–9. January 1994. doi:10.1111/j.1432-1033.1994.tb19983.x. PMID 8307032. https://epub.ub.uni-muenchen.de/2482/1/244.pdf. 
  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. 

External links