(3R)-3-hydroxybutanoyl-CoA + [(3R)-hydroxybutanoate](n) <=> [(3R)-hydroxybutanoate](n+1) + CoA
(3r)-3-hydroxybutanoyl-coa + [(3r)-hydroxybutanoate](n) <=> [(3r)-hydroxybutanoate](n+1) + coa
(3R)-3-hydroxybutanoyl-CoA + [(3R)-hydroxybutanoate](n) <=> [(3R)-hydroxybutanoate](n+1) + CoA
(3r)-3-hydroxybutanoyl-coa + [(3r)-hydroxybutanoate](n) <=> [(3r)-hydroxybutanoate](n+1) + coa