PORA and PORB, Two Light-Dependent Protochlorophyllide-Reducing Enzymes of Angiosperm Chlorophyll Biosynthesis.
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چکیده
منابع مشابه
Identification of NADPH:protochlorophyllide oxidoreductases A and B: a branched pathway for light-dependent chlorophyll biosynthesis in Arabidopsis thaliana.
Illumination releases the arrest in chlorophyll (Chl) biosynthesis in etiolated angiosperm seedlings through the enzymatic photoreduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), the first light-dependent step in chloroplast biogenesis. NADPH: Pchlide oxidoreductase (POR, EC 1.3.1.33), a nuclear-encoded plastid-localized enzyme, mediates this unique photoreduction. Paradoxic...
متن کاملldentification of NADPH : Protochlorophyllide Oxidoreductases A and B : A Branched Pathway for Light - Dependent Chlorophyll Biosynthesis in Arabidopsis thaliana '
lllumination releases the arrest in chlorophyll (Chl) biosynthesis in etiolated angiosperm seedlings through the enzymatic photoreduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), the first light-dependent step in chloroplast biogenesis. NADPH: Pchlide oxidoreductase (POR, EC 1.3.1.33), a nuclear-encoded plastid-localized enzyme, mediates this unique photoreduction. Paradoxic...
متن کاملPhotoactive Protochlorophyllide-Enzyme Complexes Reconstituted with PORA, PORB and PORC Proteins of A. thaliana: Fluorescence and Catalytic Properties
Photoactive Pchlide-POR-NADPH complexes were reconstituted using protochlorophyllide (Pchlide) and recombinant light-dependent protochlorophyllide oxidoreductase (POR) proteins, His₆-PORA, His₆-PORB and His₆-PORC, from Arabidopsis thaliana. We did not observe any differences in the kinetics of the protochlorophyllide photoreduction at room temperature among the PORA, PORB and PORC proteins. In ...
متن کاملThe extra loop distinguishing POR from the structurally related short-chain alcohol dehydrogenases is dispensable for pigment binding but needed for the assembly of light-harvesting POR-protochlorophyllide complex.
We have recently discovered a protochlorophyllide (Pchlide)-based light-harvesting complex involved in chlorophyll a biosynthesis. This complex consists of the two previously identified NADPH:protochlorophyllide oxidoreductases (PORs), PORA and PORB, their natural substrates (Pchlide b and Pchlide a, respectively), plus NADPH. These are all held together in a stoichiometry of five PORA-Pchlide ...
متن کاملTwo NADPH:Protochlorophyllide Oxidoreductases in Barley: Evidence for the Selective Disappearance of PORA during the Light-Induced Greening of Etiolated Seedlings.
Chlorophyll synthesis in barley is controlled by two different light-dependent NADPH:protochlorophyllide oxidoreductases, termed PORA and PORB. PORA is present abundantly in etioplasts but selectively disappears soon after the beginning of illumination. This negative light effect is mediated simultaneously at three different levels. First, the concentration of porA mRNA declines drastically dur...
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ژورنال
عنوان ژورنال: The Plant Cell
سال: 1996
ISSN: 1040-4651,1532-298X
DOI: 10.1105/tpc.8.5.763