EC Number   |
General Information |
Reference |
|---|
    1.5.1.8 | evolution |
the enzyme domains and activities LKR and SDH belong to a single about 120 kDa bifunctional polypeptide |
763097 |
| 1.5.1.8 | evolution |
the enzyme domains and activities LKR and SDH belong to a single about 120 kDa bifunctional polypeptide. In most plants, the enzyme is encoded by a single gene |
763097 |
| 1.5.1.8 | malfunction |
immature endosperms of high-lysine maize mutants, in addition to the bifunctional LKR/SDH polypeptide, also present a small proportion of an active monofunctional SDH |
763097 |
| 1.5.1.8 | metabolism |
the central enzymes of the saccharopine pathway (SACPATH) catalyze a transamination-like reaction involving the enzymes lysine-ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH) and the enzyme alpha-aminoadipate semialdehyde dehydrogenase (AASADH). SACPATH involves the conversion of lysine into alpha-aminoadipate by three enzymatic reactions catalyzed by the bifunctional enzyme LKR/SDH and AASADH. The LKR domain condenses lysine and alpha-ketoglutarate into saccharopine, and the SDH domain hydrolyzes saccharopine to form glutamate and alpha-aminoadipate semialdehyde, the latter of which is oxidized to alpha-aminoadipate by AASADH. The LKR domain condenses L-lysine and 2-oxoglutarate into saccharopine using NADPH as a cofactor |
763097 |
| 1.5.1.8 | metabolism |
the central enzymes of the saccharopine pathway (SACPATH) catalyze a transamination-like reaction involving the enzymes lysine-ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH) and the enzyme alpha-aminoadipate semialdehyde dehydrogenase (AASADH). SACPATH involves the conversion of lysine into alpha-aminoadipate by three enzymatic reactions catalyzed by the bifunctional enzyme LKR/SDH and AASADH. The LKR domain condenses lysine and alpha-ketoglutarate into saccharopine, and the SDH domain hydrolyzes saccharopine to form glutamate and alpha-aminoadipate semialdehyde, the latter of which is oxidized to alpha-aminoadipate by AASADH. The LKR domain condenses L-lysine and 2-oxoglutarate into saccharopine using NADPH as a cofactor. Stress-induced protein hydrolysis results in increased free lysine levels. Increased lysine pool can also result from the induction of the aspartate (AK) pathway for lysine biosynthesis |
763097 |
| 1.5.1.8 | metabolism |
the enzyme is involved in L-lysine breakdown. In Nilaparvata lugens, the degradation of L-lysine is independent from the yeast-like endosymbionts of the organism, in contrast to degradation of other amino acids, overview |
743575 |
| 1.5.1.8 | metabolism |
the enzyme is involved in L-lysine degradation |
743526 |
| 1.5.1.8 | physiological function |
gene silencing by RNAi indicates that the tick LKR/SDH plays an integral role in the osmotic regulation of water balance and development of eggs in ovary of engorged females |
700907 |
| 1.5.1.8 | physiological function |
involvement of the SACPATH pathway in plant responses to abiotic and biotic stresses, overview. The induction of LKR activity by phosphorylation in a lysine-dependent manner implies that this enzyme is quickly activated to produce saccharopine once lysine levels start rising. The immediate increase in LKR activity stimulates increases in SDH activity, as the two activities occur within the same polypeptide. The immediate consequence of these two reaction steps is the increase in the concentration of alpha-aminoadipate semialdehyde, which would require an increase in AASADH and perhaps P5CR activities to maintain alpha-aminoadipate semialdehyde concentrations below toxic levels |
763097 |
