Conversion of Chlorophyll b to Chlorophyll a via 7-Hydroxymethyl Chlorophyll

Itô, Hisashi; Ohtsuka, Tatsuyuki; Tanaka, Ayumi

doi:10.1074/jbc.271.3.1475

Cited by 137 publications

(97 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This enzyme had originally been implicated in the Chl b to Chl a reaction cycle of chloroplasts during photosynthetic acclimation and leaf senescence (26). But it is also highly active in etioplasts, as shown in this and previous studies (22)(23)(24)(25)(26). We assume that 7-formyl reductase may be involved in fine tuning the amounts of Pchlide b and Pchlide a and thereby could regulate the steady-state level of LHPP in etioplasts.…”

Section: Discussionmentioning

confidence: 69%

“…By analogy, this enzyme activity was found to also convert the nonesterified precursor of Chl b, Chlide b, as well as pyrochlorophyllide b and the magnesium-free pheophorbide b into the respective Chl a and 7-hydroxy compounds (23)(24)(25)(26).…”

Section: Resultsmentioning

confidence: 99%

“…In a recent paper, Scheumann et al (21) even generally questioned the existence of Pchlide b, but at the same time demonstrated that barley etioplasts rapidly convert exogenously added zinc protopheophorbide b (ZnPPb) to ZnPPa. This prompted us to conclude that Chl(ide) b reductase, presumably responsible for this conversion (22)(23)(24)(25)(26), could also metabolize the endogenously occurring Pchlide b to Pchlide a.…”

Section: For a Summary)mentioning

confidence: 99%

See 2 more Smart Citations

In Situ Conversion of Protochlorophyllideb to Protochlorophyllide a in Barley

Reinbothe¹,

Pollmann²,

Reinbothe³

2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 69%

Section: Resultsmentioning

confidence: 99%

Section: For a Summary)mentioning

confidence: 99%

See 1 more Smart Citation

In Situ Conversion of Protochlorophyllideb to Protochlorophyllide a in Barley

Reinbothe¹,

Pollmann²,

Reinbothe³

2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

“…The two enzymes catalyzing these consecutive reactions, Chl b reductase and hydroxymethyl Chl a reductase (HCAR), have different biochemical properties; while the latter is a ferredoxin-dependent, stroma-localized enzyme, Chl b reductase localizes to the thylakoid membrane and requires NADPH as electron source (Ito et al 1996;Scheumann et al 1998Scheumann et al , 1999. Genes encoding both enzymes have recently been identified Meguro et al 2011).…”

Section: Chlorophyll Catabolic Enzymesmentioning

confidence: 99%

Update on the biochemistry of chlorophyll breakdown

2012

View full text Add to dashboard Cite

In land plants, chlorophyll is broken down to colorless linear tetrapyrroles in a highly conserved multi-step pathway. The pathway is termed the 'PAO pathway', because the opening of the chlorine macrocycle present in chlorophyll catalyzed by pheophorbide a oxygenase (PAO), the key enzyme of the pathway, provides the characteristic structural basis found in all further downstream chlorophyll breakdown products. To date, most of the biochemical steps of the PAO pathway have been elucidated and genes encoding many of the chlorophyll catabolic enzymes been identified. This review summarizes the current knowledge on the biochemistry of the PAO pathway and provides insight into recent progress made in the field that indicates that the pathway is more complex than thought in the past. Abstract In land plants, chlorophyll is broken down to colorless linear tetrapyrroles in a highly conserved multistep pathway. The pathway is termed the 'PAO pathway', because the opening of the chlorine macrocycle present in chlorophyll catalyzed by pheophorbide a oxygenase (PAO), the key enzyme of the pathway, provides the characteristic structural basis found in all further downstream chlorophyll breakdown products. To date, most of the biochemical steps of the PAO pathway have been elucidated and genes encoding many of the chlorophyll catabolic enzymes been identified. This review summarizes the current knowledge on the biochemistry of the PAO pathway and provides insight into recent progress made in the field that indicates that the pathway is more complex than thought in the past.

show abstract

“…In vivo, Pchlide a may either be freshly synthesized from protoporphyrin IX via the Mg branch of the C5-pathway or could alternatively be formed from excess Pchlide b by virtue of 7-formyl reductase present in the prolamellar body. According to previous and recent work, barley etioplasts contain 7-formyl reductase activity which converts a wide range of 6-type porphyrins and chlorins to their a-type compounds [27,[74][75][76][77]. A presumed intermediate in the conversión of Pchlide b to Pchlide a is 7-OH-Pchlide a detected in this (Fig.…”

Section: Light-induced Dissociation Oflhppmentioning

confidence: 99%

LHPP, the light-harvesting NADPH:protochlorophyllide (Pchlide) oxidoreductase:Pchlide complex of etiolated plants, is developmentally expressed across the barley leaf gradient

et al. 2004

View full text Add to dashboard Cite

NADPH:protochlorophyllide oxidoreductase is a key enzyme for the light-induced greening of etiolated angiosperm plants. In barley, two POR proteins exist termed PORA and PORB that have previously been proposed to stmcturally and functionally cooperate in terms of a higher molecular mass light-harvesting complex named LHPP, in the prolamellar body of etioplasts [Nature 397 (1999) 80]. In this study we examined the expression pattern of LHPP during seedling etiolation and de-etiolation under different experimental conditions. Our results show that LHPP is developmentally expressed across the barley leaf gradient. We further provide evidence that LHPP operates both in plants that etiolate completely before being exposed to white light and in plants that etiolate only partially and begin light-harvesting as soon as traces of light become available in the uppermost parts of the soil. As a result of light absorption, in either case LHPP converts Pchlide a to chlorophyllide (Chlide) a and in turn disintegrates. The released Chlide a, as well as Chlide b produced upon LHPP's light-dependent dissociation, which leads to the activation of the PORA as a Pchlide £-reducing enzyme, then bind to homologs of water-soluble chlorophyll proteins of Brassicaceae. We propose that these proteins transfer Chlide a and Chlide b\o the thylakoids, where their esterification with phytol and assembly into the photosynthetic membrane complexes ultimately takes place. Presumably due to the tight coupling of LHPP synthesis and degradation, as well as WSCP formation and photosynthetic membrane assembly, eflficient photo-protection is conferred onto the plant.

show abstract

Conversion of Chlorophyll b to Chlorophyll a via 7-Hydroxymethyl Chlorophyll

Cited by 137 publications

References 26 publications

In Situ Conversion of Protochlorophyllideb to Protochlorophyllide a in Barley

In Situ Conversion of Protochlorophyllideb to Protochlorophyllide a in Barley

Update on the biochemistry of chlorophyll breakdown

LHPP, the light-harvesting NADPH:protochlorophyllide (Pchlide) oxidoreductase:Pchlide complex of etiolated plants, is developmentally expressed across the barley leaf gradient

Contact Info

Product

Resources

About