Dihydroxyacid dehydratase that catalyzes the third step in the common pathway leading to biosynthesis of branched-chain amino acids (PubMed:23028460). Catalyzes the dehydration of (2R,3R)-2,3-dihydroxy-3-methylpentanoate (2,3-dihydroxy-3-methylvalerate) into 2-oxo-3-methylpentanoate (2-oxo-3-methylvalerate) and of (2R)-2,3-dihydroxy-3-methylbutanoate (2,3-dihydroxyisovalerate) into 2-oxo-3-methylbutanoate (2-oxoisovalerate), the penultimate precursor to L-isoleucine and L-valine, respectively (By similarity). IlvC and the branched-chain amino acid biosynthesis are crucial for virulence and may be a potential target to develop antifungal agents (PubMed:23028460). (2R)-2,3-dihydroxy-3-methylbutanoate = 3-methyl-2-oxobutanoate + H2O (2R,3R)-2,3-dihydroxy-3-methylpentanoate = (S)-3-methyl-2-oxopentanoate + H2O Binds 1 [2Fe-2S] cluster per subunit. DHAD activity is inhibited in dose-dependent manner by 2-hydroxy-3-methylbutyric acid with an IC(50) of about 8 mM. Amino-acid biosynthesis; L-isoleucine biosynthesis; L-isoleucine from 2-oxobutanoate: step 3/4. Amino-acid biosynthesis; L-valine biosynthesis; L-valine from pyruvate: step 3/4. Requires supplementation with isoleucine and valine for growth (PubMed:23028460). Results in considerably lower kidney tissue burden in murine infection models (PubMed:23028460). Belongs to the IlvD/Edd family.