(R)-hydratase [(R)-specific enoyl-CoA hydratase]. Catalyzes the hydration of trans-2-enoyl CoA to (R)-3-hydroxyacyl-CoA as part of the PHA (polyhydroxyalkanoate) biosynthetic pathway. The structure of the monomer includes a five-strand antiparallel beta-sheet wrapped around a central alpha helix, referred to as a hot dog fold. The active site lies within a substrate-binding tunnel formed by the homodimer. Other enzymes with this fold include MaoC dehydratase, Hydratase-Dehydrogenase-Epimerase protein (HDE), and the fatty acid synthase beta subunit.