. "Catalysis of the reaction: 4-hydroxybutanoyl-CoA = vinylacetyl-CoA + H2O." . . "4-hydroxybutanoyl-CoA dehydratase activity" . "4-hydroxybutanoyl-CoA hydro-lyase" . "4-hydroxybutyryl-CoA dehydratase activity" . "gamma-hydroxybutanoyl-CoA dehydratase activity" . "gamma-hydroxybutyryl-CoA dehydratase activity" . . .