The enzyme (R)-2-methylmalate dehydratase () catalyzes the chemical reaction
This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is . Other names in common use include , and . This enzyme participates in valine, leucine and isoleucine biosynthesis and c5-branched dibasic acid metabolism. It employs one cofactor, iron.