pheophorbide a oxygenase [EC:1.14.15.17]

PMID:14657372

Pruzinska A, Tanner G, Anders I, Roca M, Hortensteiner S

Chlorophyll breakdown: pheophorbide a oxygenase is a Rieske-type iron-sulfur protein, encoded by the accelerated cell death 1 gene.

Proc Natl Acad Sci U S A 100:15259-64 (2003)
DOI:10.1073/pnas.2036571100

[ath:AT3G44880]

PMID:14701922

Tanaka R, Hirashima M, Satoh S, Tanaka A

The Arabidopsis-accelerated cell death gene ACD1 is involved in oxygenation of pheophorbide a: inhibition of the pheophorbide a oxygenase activity does not lead to the "stay-green" phenotype in Arabidopsis.

Plant Cell Physiol 44:1266-74 (2003)

[ath:AT3G44880]

Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With reduced iron-sulfur protein as one donor, and incorporation of one atom of oxygen into the other donor

pheophorbide-a,ferredoxin:oxygen oxidoreductase (biladiene-forming)

pheophorbide a + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ + O2 = red chlorophyll catabolite + 2 oxidized ferredoxin [iron-sulfur] cluster (overall reaction) [RN:R08921];
(1a) pheophorbide a + 2 reduced ferredoxin [iron-sulfur] cluster + 2 H+ + O2 = epoxypheophorbide a + 2 oxidized ferredoxin [iron-sulfur] cluster + H2O [RN:R11227];
(1b) epoxypheophorbide a + H2O = red chlorophyll catabolite (spontaneous) [RN:R11228]

R08921 R11227 R11228

pheophorbide a [CPD:C18021];
reduced ferredoxin [iron-sulfur] cluster [CPD:C00138];
H+ [CPD:C00080];
O2 [CPD:C00007];
epoxypheophorbide a [CPD:C21192];
H2O [CPD:C00001]

This enzyme catalyses a key reaction in chlorophyll degradation, which occurs during leaf senescence and fruit ripening in higher plants. The enzyme from Arabidopsis contains a Rieske-type iron-sulfur cluster [2] and requires reduced ferredoxin, which is generated either by NADPH through the pentose-phosphate pathway or by the action of photosystem I [4]. While still attached to this enzyme, the product is rapidly converted into primary fluorescent chlorophyll catabolite by the action of EC 1.3.7.12, red chlorophyll catabolite reductase [2,6]. Pheophorbide b acts as an inhibitor. In 18O2 labelling experiments, only the aldehyde oxygen is labelled, suggesting that the other oxygen atom may originate from H2O [1].

EC 1.14.15.17 created 2007 as EC 1.14.12.20, transferred 2016 to EC 1.14.15.17

1  [PMID:9624113]

Hortensteiner S, Wuthrich KL, Matile P, Ongania KH, Krautler B.

The key step in chlorophyll breakdown in higher plants. Cleavage of pheophorbide a macrocycle by a monooxygenase.

J. Biol. Chem. 273 (1998) 15335-9.

2  [PMID:14657372]

Pruzinska A, Tanner G, Anders I, Roca M, Hortensteiner S.

Chlorophyll breakdown: pheophorbide a oxygenase is a Rieske-type iron-sulfur protein, encoded by the accelerated cell death 1 gene.

Proc. Natl. Acad. Sci. U. S. A. 100 (2003) 15259-64.

[ath:AT3G44880]

3  [PMID:16844830]

Chung DW, Pruzinska A, Hortensteiner S, Ort DR.

The role of pheophorbide a oxygenase expression and activity in the canola green seed problem.

Plant. Physiol. 142 (2006) 88-97.

4  [PMID:12223835]

Rodoni S, Muhlecker W, Anderl M, Krautler B, Moser D, Thomas H, Matile P, Hortensteiner S.

Chlorophyll Breakdown in Senescent Chloroplasts (Cleavage of Pheophorbide a in Two Enzymic Steps).

Plant. Physiol. 115 (1997) 669-676.

5  [PMID:16669755]

Hortensteiner S.

Chlorophyll degradation during senescence.

Annu. Rev. Plant. Biol. 57 (2006) 55-77.

6  [PMID:17237353]

Pruzinska A, Anders I, Aubry S, Schenk N, Tapernoux-Luthi E, Muller T, Krautler B, Hortensteiner S.

In vivo participation of red chlorophyll catabolite reductase in chlorophyll breakdown.

Plant. Cell. 19 (2007) 369-87.