EC Number   |
General Information |
Reference |
|---|
    1.14.13.81 | malfunction |
a Chl27-antisense Arabidopsis mutant accumulates the cyclase substrate magnesium-protoporphyrin IX monomethyl ester and does not produce protochlorophyllide a |
700629 |
| 1.14.13.81 | malfunction |
a Rubrivivax gelatinosus strain with disrupted acsF gene cannot synthesize bacteriochlorophyll under oxygenated conditions but accumulates the substrate magnesium-protoporphyrin IX monomethyl ester, in contrast, under low-oxygene conditions the phenotype is similar to the wild-type, an alternative pathway for the reaction exists vie the bchE genes |
700629 |
| 1.14.13.81 | physiological function |
an essential enzyme during chlorophyll (Chl) biosynthesis. The enzyme subunit protein YL-1 is required for plastid membrane stability. The formation of the isocyclic ring is an aerobic reaction catalyzed by MPEC in chloroplasts, which controls the conversion of magnesium-protoporphyrin IX 13-monomethyl ester to divinyl protochlorophyllide (DVpchlide). The function of YL-1 in MPEC complex is essential for normal chlorophyll biosynthesis |
746223 |
| 1.14.13.81 | malfunction |
chlorophyll biosynthesis upstream genes are highly expressed in the yl-1 mutant, while downstream genes are compromised, indicating that enzyme MPEC plays a pivotal role in the chlorophyll biosynthesis. The yl-1 mutant shows a yellow leaf and panicle phenotype with reduced chlorophyll accumulation through the whole growth phases. Mutant yl-1 exhibits the temperature-independent yellow leaf phenotype, it presents abnormal chloroplast development and attenuated photosynthetic efficiency. The mutant yl-1 affects mRNA accumulation levels of Chl biosynthesis process |
746223 |
| 1.14.13.81 | malfunction |
crd1 strains fail to accumulate photosystem 1 (PS 1) and light-harvesting complex 1 (LHC 1) during hypoxia or copper deficiency, and have reduced amounts of LHC 2, Crd1 abundance is increased in copper or oxygen deficient cells |
700629 |
| 1.14.13.81 | malfunction |
Cth1 accumulates in copper-sufficient, oxygenated cells |
700629 |
| 1.14.13.81 | physiological function |
cyclic tetrapyrroles, are among the most abundant natural pigments on Earth. They are the major absorbers of the solar energy that drives photosynthesis, and billions of tonnes of chlorophyll are synthesised annually on land and in the oceans. The decisive biosynthetic step that determines the absorption properties of chlorophyll, and more visually its green color, is the formation of the unique isocyclic fifth ring. This process involves the conversion of Mg-protoporphyrin IX monomethyl ester (MgPME) to 3,8-divinyl protochlorophyllide a (DV PChlide a), and it requires incorporation of an oxygen atom, sourced from either water or O2, indicating the existence of two mechanistically different MgPME cyclases. Most anoxygenic phototrophic bacteria utilise an O2-sensitive radical SAM enzyme containing [4Fe-4S] and cobalamin cofactors to catalyse the reaction, while oxygenic phototrophs including cyanobacteria, algae and plants, as well as some purple bacteria, adopt an O2-dependent cyclase for the reaction. Mg-protoporphyrin IX monomethyl ester (MgPME) cyclase catalyses the formation of the isocyclic ring, the hallmark of chlorins and bacteriochlorins, producing protochlorophyllide a and contributing significantly to the absorption properties of chlorophylls and bacteriochlorophylls. The diiron cluster within AcsF is reduced by ferredoxin furnished by NADPH and ferredoxin:NADP+ reductase or by direct coupling to Photosystem I photochemistry, linking cyclase to the photosynthetic electron transport chain |
765462 |
| 1.14.13.81 | malfunction |
decreased CHL27 transcript levels result in a substantial reduction of activity of MgPME cyclase and MgP monomethylester accumulation, in comparison to dexamethasone-treated wild-type seedlings |
745807 |
| 1.14.13.81 | malfunction |
deficiency of the LCAA subunit affects Ala synthesis and the accumulation of proteins in tetrapyrrole biosynthesis |
728517 |
| 1.14.13.81 | metabolism |
enzyme is involved in the protochlorophyllide a synthesis |
700711 |
