KEGG   ENZYME: 1.14.15.17
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
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 metabolism
ec01110  Biosynthesis of secondary metabolites
Orthology
K13071  pheophorbide a oxygenase
Genes
ATHAT3G44880(ACD1)
ALY9311768
CRB17886611
CSAT104710959 104780339 104790741
EUSEUTSA_v10002475mg
BRP103873062(PAO)
BNA106428557 111202294
BOE106314152
RSZ108843569
THJ104810883
CPAP110815591
CIT102625487
CICCICLE_v10028147mg
PVY116146414
MINC123224875
TCC18590461
GRA105792030
GHI107912983 107954179
GAB108488406
DZI111303747
EGR104434044
GMX100812162 778121
GSJ114374966 114379955
PVUPHAVU_011G0867001
VRA106756471
VAR108340678
VUN114169785
CCAJ109799081
APRC113857686
MTRMTR_4g057200
CAM101513298
LJALj3g3v3032090.1(Lj3g3v3032090.1)
ADU107476453
AIP107629280
AHF112736431 112785193
LANG109325727
FVE101295785
RCN112164842
PPER18773030
PMUM103326271
PAVI110755322
PDUL117630136
MDM103448044
PXB103947727(PAO)
ZJU107405855 107410684
MNT21395013
CSV101217499
CMO103500813
BHJ120082996
MCHA111020548
CMAX111469310
CMOS111464914
CPEP111782848
RCU8275254
JCU105627999
HBR110660525 110673306
MESC110613441
POP18098257
PEU105128358
PALZ118038771
JRE109000632 109001071
QSU111988433 112031559
QLO115980391
TWL119991014
VVI100256831
VRI117916257
SLY543677
SPEN107004514
SOT102579316
CANN107847505
NTA107805002 107817296
NSY104230562
NTO104101187
NAU109236990
INI109181409
ITR116026168
SIND105169951
EGT105958550
SSPL121741881 121744985
HAN110890956
ECAD122581878
LSV111886016
CCAV112519778
DCR108192785
CSIN114267306
BVG104902984
SOE110787958
CQI110691778 110730868
NNU104587323 104604584
MING122057361
TSS122650451
PSOM113310446 113338679
NCOL116266420
OSA4331611
DOSAOs03t0146400-01(Os03g0146400)
OBR102703661
BDI100840185
ATS109738799
TDC119287653 119291764
TAES101290687 123088137 123098772
TUA125552929
SBI8085484
ZMA103631716
SITA101766370
SVS117839075
PVIR120647311 120691099
PHAI112874891
PDA103723245
EGU105043024
MUS103982755
DCT110105134
PEQ110024671
AOF109839369
ATR18432947
SMOSELMODRAFT_174928 SELMODRAFT_177205
PPP112279655 112284490
EHXEMIHUDRAFT_205252
 » show all
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)
DOI:10.1104/pp.115.2.669
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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