Homoserine dehydrogenase
In enzymology, a homoserine dehydrogenase (EC 1.1.1.3) is an enzyme that catalyzes the chemical reaction
- L-homoserine + NAD(P)+ L-aspartate 4-semialdehyde + NAD(P)H + H+
| Homoserine dehydrogenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Homoserine dehydrogenase complex with NAD+ analogue and L-homoserine. | |||||||||
| Identifiers | |||||||||
| Symbol | Homoserine_dh | ||||||||
| Pfam | PF00742 | ||||||||
| InterPro | IPR001342 | ||||||||
| PROSITE | PDOC00800 | ||||||||
| SCOP2 | 1ebu / SCOPe / SUPFAM | ||||||||
| |||||||||
| Homoserine dehydrogenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Homoserine dehydrogenase homotetramer, Thiobacillus denitrificans | |||||||||
| Identifiers | |||||||||
| EC no. | 1.1.1.3 | ||||||||
| CAS no. | 9028-13-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
The 2 substrates of this enzyme are L-homoserine and NAD+ (or NADP+), whereas its 3 products are L-aspartate 4-semialdehyde, NADH (or NADPH), and H+.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-homoserine:NAD(P)+ oxidoreductase. Other names in common use include HSDH, and HSD.
Homoserine dehydrogenase catalyses the third step in the aspartate pathway; the NAD(P)-dependent reduction of aspartate beta-semialdehyde into homoserine. Homoserine is an intermediate in the biosynthesis of threonine, isoleucine, and methionine.