3-methyl-2-oxobutanoate hydroxymethyltransferase

In enzymology, a 3-methyl-2-oxobutanoate hydroxymethyltransferase () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are 5,10-methylenetetrahydrofolate, 3-methyl-2-oxobutanoate, and H2O, whereas its two products are tetrahydrofolate and 2-dehydropantoate.
This enzyme belongs to the family of transferases that transfer one-carbon groups, specifically the hydroxymethyl-, formyl- and related transferases. The systematic name of this enzyme class is 5,10-methylenetetrahydrofolate:3-methyl-2-oxobutanoate hydroxymethyltransferase. Other names in common use include alpha-ketoisovalerate hydroxymethyltransferase, dehydropantoate hydroxymethyltransferase, ketopantoate hydroxymethyltransferase, oxopantoate hydroxymethyltransferase, 5,10-methylene tetrahydrofolate:alpha-ketoisovalerate, and hydroxymethyltransferase. This enzyme participates in pantothenate and coa biosynthesis.
Structural studies.
As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes , , , and .