EC number 1.1.1.31 ExPASy NiceZyme view | CAS number 9028-39-1 | |
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In enzymology, a 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) also known as β-hydroxyisobutyrate dehydrogenase or 3-hydroxyisobutyrate dehydrogenase, mitochondrial (HIBADH) is an enzyme that in humans is encoded by the HIBADH gene.
Contents
3-Hydroxyisobutyrate dehydrogenase catalyzes the chemical reaction:
3-hydroxy-2-methylpropanoate + NAD+Thus, the two substrates of this enzyme are 3-hydroxy-2-methylpropanoate and NAD+, whereas its 3 products are 2-methyl-3-oxopropanoate, NADH, 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 3-hydroxy-2-methylpropanoate:NAD+ oxidoreductase. This enzyme participates in valine, leucine and isoleucine degradation.
Function
3-hydroxyisobutyrate dehydrogenase is a tetrameric mitochondrial enzyme that catalyzes the NAD+-dependent, reversible oxidation of 3-hydroxyisobutyrate, an intermediate of valine catabolism, to methylmalonate semialdehyde.
Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1WP4, 2CVZ, 2GF2, 2H78, and 2I9P.