KEGG   ENZYME: 1.14.15.17Help
Entry
EC 1.14.15.17               Enzyme                                 

Name
pheophorbide a oxygenase;
pheide a monooxygenase;
pheide a oxygenase;
PaO;
PAO
Class
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
BRITE hierarchy
Sysname
pheophorbide-a,ferredoxin:oxygen oxidoreductase (biladiene-forming)
Reaction(IUBMB)
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]
Reaction(KEGG)
Substrate
pheophorbide a [CPD:C18021];
reduced ferredoxin [iron-sulfur] cluster [CPD:C00138];
H+ [CPD:C00080];
O2 [CPD:C00007];
epoxypheophorbide a [CPD:C21192];
H2O [CPD:C00001]
Product
red chlorophyll catabolite [CPD:C18022];
oxidized ferredoxin [iron-sulfur] cluster [CPD:C00139];
epoxypheophorbide a [CPD:C21192];
H2O [CPD:C00001]
Comment
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].
History
EC 1.14.15.17 created 2007 as EC 1.14.12.20, transferred 2016 to EC 1.14.15.17
Pathway
ec00860  Porphyrin and chlorophyll metabolism
ec01110  Biosynthesis of secondary metabolites
Orthology
K13071  pheophorbide a oxygenase
Genes
ATH: AT3G44880(ACD1)
ALY: ARALYDRAFT_905628
CRB: 17886611
CSAT: 104698851 104710959 104780339 104790741
EUS: EUTSA_v10002475mg
BRP: 103873062(PAO)
BNA: 106428543 106428557 111202294
BOE: 106314152
THJ: 104810883
CPAP: 110815591
CIT: 102625487
TCC: 18590461
GRA: 105792030
EGR: 104434044
VRA: 106756471
VAR: 108340678
CCAJ: 109799081
CAM: 101513298
LJA: Lj3g3v3032090.1(Lj3g3v3032090.1)
ADU: 107476453
AIP: 107629280
LANG: 109325727
FVE: 101295785
PPER: 18773030
PMUM: 103326271
PAVI: 110755322
MDM: 103448044
PXB: 103947727(PAO)
CSV: 101217499(CSPAO)
MCHA: 111020548
CMAX: 111469310
CMOS: 111464914
CPEP: 111782848
RCU: 8275254
JCU: 105627999
VVI: 100256831
SLY: 543677
SPEN: 107004514
SOT: 102579316
CANN: 107847505(LLS1)
NSY: 104230562
NTO: 104101187
INI: 109181409
SIND: 105169951
OEU: 111384479
DCR: 108192785
BVG: 104902984
SOE: 110787958
OSA: 4331611
DOSA: Os03t0146400-01(Os03g0146400)
OBR: 102703661
BDI: 100840185
ATS: 109738799(LOC109738799)
SBI: 8085484
ZMA: 103631716
SITA: 101766370
PDA: 103723245
EGU: 105043024
MUS: 103982755
DCT: 110105134
AOF: 109839369
ATR: 18432947
MIS: MICPUN_59870(TIC55-4)
MPP: MICPUCDRAFT_50506(TIC55-6)
SMIN: v1.2.005309.t1(symbB.v1.2.005309.t1)
 » show all
Taxonomy
Reference
1  [PMID:9624113]
  Authors
Hortensteiner S, Wuthrich KL, Matile P, Ongania KH, Krautler B.
  Title
The key step in chlorophyll breakdown in higher plants. Cleavage of pheophorbide a macrocycle by a monooxygenase.
  Journal
J Biol Chem 273:15335-9 (1998)
DOI:10.1074/jbc.273.25.15335
Reference
2  [PMID:14657372]
  Authors
Pruzinska A, Tanner G, Anders I, Roca M, Hortensteiner S.
  Title
Chlorophyll breakdown: pheophorbide a oxygenase is a Rieske-type iron-sulfur protein, encoded by the accelerated cell death 1 gene.
  Journal
Proc Natl Acad Sci U S A 100:15259-64 (2003)
DOI:10.1073/pnas.2036571100
  Sequence
[ath:AT3G44880]
Reference
3  [PMID:16844830]
  Authors
Chung DW, Pruzinska A, Hortensteiner S, Ort DR.
  Title
The role of pheophorbide a oxygenase expression and activity in the canola green seed problem.
  Journal
Plant Physiol 142:88-97 (2006)
DOI:10.1104/pp.106.084483
Reference
4  [PMID:12223835]
  Authors
Rodoni S, Muhlecker W, Anderl M, Krautler B, Moser D, Thomas H, Matile P, Hortensteiner S.
  Title
Chlorophyll Breakdown in Senescent Chloroplasts (Cleavage of Pheophorbide a in Two Enzymic Steps).
  Journal
Plant Physiol 115:669-676 (1997)
Reference
5  [PMID:16669755]
  Authors
Hortensteiner S.
  Title
Chlorophyll degradation during senescence.
  Journal
Annu Rev Plant Biol 57:55-77 (2006)
DOI:10.1146/annurev.arplant.57.032905.105212
Reference
6  [PMID:17237353]
  Authors
Pruzinska A, Anders I, Aubry S, Schenk N, Tapernoux-Luthi E, Muller T, Krautler B, Hortensteiner S.
  Title
In vivo participation of red chlorophyll catabolite reductase in chlorophyll breakdown.
  Journal
Plant Cell 19:369-87 (2007)
DOI:10.1105/tpc.106.044404
Other DBs
ExplorEnz - The Enzyme Database: 1.14.15.17
IUBMB Enzyme Nomenclature: 1.14.15.17
ExPASy - ENZYME nomenclature database: 1.14.15.17
BRENDA, the Enzyme Database: 1.14.15.17

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