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EC 1.13.11.51 Details
show Brenda entryEC number
1.13.11.51
Accepted name
9-cis-epoxycarotenoid dioxygenase
Reaction
(1) a 9-cis-epoxycarotenoid + O2 = 2-cis,4-trans-xanthoxin + a 12′-apo-carotenal;;(2) 9-cis-violaxanthin + O2 = 2-cis,4-trans-xanthoxin + (3S,5R,6S)-5,6-epoxy-3-hydroxy-5,6-dihydro-12′-apo-β-caroten-12′-al;;(3) 9′-cis-neoxanthin + O2 = 2-cis,4-trans-xanthoxin + (3S,5R,6R)-5,6-dihydroxy-6,7-didehydro-5,6-dihydro-12′-apo-β-caroten-12′-al
Other name(s)
nine-cis-epoxycarotenoid dioxygenase,
NCED,
AtNCED3,
PvNCED1,
VP14
Systematic name
9-cis-epoxycarotenoid 11,12-dioxygenase
CAS registry number
199877-10-6
Comment
Requires iron(II). Acts on 9-cis-violaxanthin and 9′-cis-neoxanthin but not on the all-trans isomers [2,3]. In vitro, it will cleave 9-cis-zeaxanthin. Catalyses the first step of abscisic-acid biosynthesis from carotenoids in chloroplasts, in response to water stress. The other enzymes involved in the abscisic-acid biosynthesis pathway are EC 1.1.1.288 (xanthoxin dehydrogenase), EC 1.2.3.14 (abscisic-aldehyde oxidase) and EC 1.14.13.93 [(+)-abscisic acid 8′-hydroxylase].
History
created 2005
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1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.6.2.1 created 1961, deleted 1965 1.6.2.3 created 1972, deleted 1965 1.6.99.4 created 1965, deleted 1972 1.6.99.8 created 1972, deleted 2002 1.6.99.9 created 1972, deleted 2002 1.6.99.10 created 1978, deleted 1981 1.6.99.11 created 1989, deleted 2002 1.6.99.12 created 1989, deleted 2002 1.6.99.13 created 1992, deleted 2002 1.13.11.21 created 1972, deleted 2001
