Activity of Fe—S cluster requiring proteins

A method of making isobutanol comprising:

• (a) providing a recombinant yeast host cell comprising:
• (i)at least one heterologous polynucleotide encoding a dihydroxy-acid dehydratase enzyme, wherein the dihydroxy-acid dehydratase enzyme has an amino acid sequence with at least 95% identity to SEQ ID NO:
• 958, and
• (ii) at least one deletion in an endogenous gene encoding a polypeptide affecting Fe—S cluster biosynthesis, wherein the gene encoding the polypeptide affecting Fe—S cluster biosynthesis is selected from Fe Repressor of Activation-2 (FRA2), glutaredoxin-3 (GRX3), and CCC1,
• wherein the recombinant yeast host cell produces isobutanol;
• and
• (b) contacting the recombinant yeast host cell of (a) with a fermentable carbon substrate in a fermentation medium under conditions wherein isobutanol is produced.