Compound as reactive (1)

13-hydroxylupanine + (E)-2-methylcrotonoyl-CoA → coenzyme A + 13-[(E)-2-methylcrotonoyl]oxylupanine

Compound as product (1)

an oxidized electron donor + 2-methylbutanoyl-CoA → a reduced electron donor + (E)-2-methylcrotonoyl-CoA

Reversible reaction (3)

3-hydroxyisovaleryl-CoA ↔ H₂O + (E)-2-methylcrotonoyl-CoA

(2S,3S)-3-hydroxy-2-methylbutanoyl-CoA ↔ H₂O + (E)-2-methylcrotonoyl-CoA

FAD + 2-methylbutanoyl-CoA ↔ FADH₂ + (E)-2-methylcrotonoyl-CoA