Scheme 8.
Enzymatic carboxylation of coenzyme A (CoA) thioesters. (a) Conversion of acetyl CoA into ethylmalonyl CoA through a multistep reaction involving a carboxylation step, catalyzed by a Rhodobacter sphaeroides lysate. [82] (b) Carboxylation of propionyl CoA catalyzed by crotonyl CoA carboxylase/reductase (CCR) [82] (c) Substrate scope of carboxylating enoyl thioester reductases (ECRs). Three ECRs (RevT from Streptomyces sp., CinF from Streptomyces sp., and EcrSh from Streptomyces hygroscopicus) showed broad substrate scope for α,β‐unsaturated CoA‐thioesters. RevT, CinF, EcrSh afforded moderate to excellent conversion of the presented substrates (40–100 % conversion). [36]