4-methylpentanoyl-CoA + (2R)-hydroxy-4-methylpentanoate <=> (R)-2-hydroxy-4-methylpentanoyl-CoA + 4-methylpentanoate
4-methylpentanoyl-coa + (2r)-hydroxy-4-methylpentanoate <=> (r)-2-hydroxy-4-methylpentanoyl-coa + 4-methylpentanoate