EC Number   |
General Information |
Reference |
|---|
   4.4.1.9 | evolution |
the ability of Pierid species to safely handle cyanide contributed to the primary host shift from Fabales to Brassicales that occured about 75 million years ago and was followed by Pierid species diversification |
730696 |
| 4.4.1.9 | evolution |
the enzyme is a member of the beta-substituted alanine synthase (BSAS) family, structure and substrate specificity comparisons with another family member, O-acetylserine sulfhydrylase, EC 2.5.1.47, from Glycine max. This enzyme prefers O-acetylserine versus Cys by 23fold and sulfide by 270fold over CN- |
730601 |
| 4.4.1.9 | evolution |
the gene encoding the enzyme was transferred to the genome of the spider mite Tetranychus urticae perhaps a few hundred million years ago, it is horizontally acquired from bacteria. An equivalent gene is also found in moths and butterflies, which explains why these insects can thrive on plants that produce hydrogen cyanide. Lateral gene transfer from bacteria to animals, overview |
729637 |
| 4.4.1.9 | malfunction |
enzyme knockout leads to an increased level of cyanide in the roots and leaves and a severe defect in root hair morphogenesis, suggesting that cyanide acts as a signaling factor in root developmen. The CYS-C1 loss-of-function mutation is not toxic for the plant |
730655 |
| 4.4.1.9 | more |
comparison of the open active site wild-type enzyme and the closed active site K95A mutant monomer structures, overview |
730601 |
| 4.4.1.9 | more |
rice seedling take up ferri-cyanide and KCN, but metabolism of KCN in rice seedlings is largely proceeded through the beta-cyanoalanine pathway, while ferricyanide is assimilated through an unreported degradation pathway. |
729635 |
| 4.4.1.9 | physiological function |
cyanide must be rapidly detoxified and metabolized by the plant to maintain the concentration below toxic levels in Arabidopsis plants through the mitochondrial beta-cyanoalanine synthase. During compatible and incompatible plant-bacteria interactions, cyanide accumulation and CYS-C1 gene expression are negatively correlated. Enzyme mutation increases both plant tolerance to biotrophic pathogens and their susceptibility to necrotrophic fungi. The enzyme is essential for maintaining non-toxic concentrations of cyanide in the mitochondria to facilitate cyanide's role in signaling |
730655 |
| 4.4.1.9 | physiological function |
exposure of seedlings to 100 microM KCN for 4 d in nitrogen-replete or nitrogen-free nutrient solution. Activity of both cyanoalanine synthase and asparaginase is significantly higher for the nitrogen-free cyanide-containing solution as compared to plants from the nitrogen-replete solution. The cyanide treatment in the presence of nitrogen is generally intermediate to these two other treatments but is not significantly different from the control treatment |
716028 |
| 4.4.1.9 | physiological function |
T-DNA insertion mutants of the mitochondrial beta-cyanoalanine synthase CYS-C1 are defective in root hair formation and accumulate cyanide in root tissues. The root hair defect is phenocopied in wild-type plants by the exogenous addition of cyanide to the growth medium and is reversed by the addition of hydroxocobalamin or by genetic complementation with the CYS-C1 gene. Hydroxocobalamin not only recovers the root phenotype of the mutant but also the formation of reactive oxygen species at the initial step of root hair tip growth. Cyanide accumulation acts as a repressive signal for several genes encoding enzymes involved in cell wall rebuilding and the formation of the root hair tip as well as genes involved in ethylene signaling and metabolism |
716516 |
| 4.4.1.9 | physiological function |
the enzyme detoxifies cyanide, larvae incorporate cyanide into beta-cyanoalanine and thiocyanide |
730696 |
