3-hydroxyisobutyrate dehydrogenase

3-hydroxyisobutyrate dehydrogenase
Identifiers
EC number	1.1.1.31
CAS number	Template:CAS
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 / EGO
Search PMC articles PubMed articles NCBI proteins

3-hydroxyisobutyrate dehydrogenase
250px PDB rendering based on 2gf2.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 2GF2, 2I9P
Identifiers
Symbols	HIBADH ; NS5ATP1
External IDs	OMIM: 608475 MGI: 1889802 HomoloGene: 15088 GeneCards: HIBADH Gene
EC number	1.1.1.31
Gene ontology Molecular function • phosphogluconate dehydrogenase (decarboxylating) activity • 3-hydroxyisobutyrate dehydrogenase activity • NAD binding Cellular component • mitochondrial matrix Biological process • valine catabolic process • branched-chain amino acid catabolic process • cellular nitrogen compound metabolic process • small molecule metabolic process • oxidation-reduction process Sources: Amigo / QuickGO
RNA expression pattern
File:PBB GE HIBADH gnf1h05976 at tn.png
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	11112	58875
Ensembl	ENSG00000106049	ENSMUSG00000029776
UniProt	P31937	Q99L13
RefSeq (mRNA)	NM_152740	NM_145567
RefSeq (protein)	NP_689953	NP_663542
Location (UCSC)	Chr 7: 27.53 – 27.66 Mb	Chr 6: 52.55 – 52.64 Mb
PubMed search	[1]	[2]

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.

3-Hydroxyisobutyrate dehydrogenase catalyzes the chemical reaction:

3-hydroxy-2-methylpropanoate + NAD⁺ $\rightleftharpoons$ 2-methyl-3-oxopropanoate + NADH + H⁺

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.