Prenylation of Benzoic Acid Derivatives Catalyzed by a Transferase from Escherichia coli Overproduction: Method Development and Substrate Specificity

Biosynthesis of Menaquinone (Vitamin K 2 ) and Ubiquinone (Coenzyme Q)

“…Compounds substituted at C-5 with OH, NH 2 , Cl, or CO-CH 3 groups were used as substrates by the enzyme. Similarly, compounds with hydroxyl groups at C-4, C-5 and C-6 or hydroxyl group at C-4, C-6 and methyl group at C-5 were substrates (169). …”

Enzymatic C–C-Coupling Prenylation: Bioinformatics – Modelling – Mechanism – Protein-Redesign – Biocatalytic Application

“…prenylated in the meta-position of the benzoic acid core. [48] This substrate specificity can be explained based on a Friedel-Crafts (S N 1)-like mechanism which was supported by semiempirical quantum mechanical PM3 calculations corresponding to Scheme 3. [49] Substrates have to pass an activation barrier to form the σ-complex which is considerably lower for substrates (~80 kJ/mol) than for non-substrates.…”

“…Furthermore, the specificity of the enzyme with regard to the accepted and transferred polyprenyl moieties was characterised. [48] In addition to geranylpyrophosphate, geranylgeranylpyrophosphate and octaprenylpyrophosphate several non-natural methallyldiphosphates [47] are also accepted as second substrates. Among these, it was surprising that geranylpyrophosphate was the fastest substrate transferred, whereas the longer ones are relevant for the in vivo participation in the ubiquinone biosynthesis and might be expected to be evolutionary more relevant.…”

“…However, the direct prenylation of p-hydroxybenzoic acid could be achieved with ubiA-prenyltransferase from E. coli (Scheme 4). [48,54,55] Additionally other enzymes (e.g. LtxC [46] ) are known not to be related to any of the sequences described above; a hint on the existence of further classes of aromatic prenyltransferases.…”

“…In vivo, the enzyme transfers diphosphorylated acyclic trans-oligoprenyl moieties (diphosphorylated terpene alcohols) to the meta-position of p-hydroxybenzoic acid (Scheme 2). [48] The enzyme accepts a reasonable number of different aromatic substrates. Thus, it could be shown that not only the natural substrate 4-hydroxybenzoic acid but also 4-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3-amino-4-hydroxybenzoic acid, various halogenated 4-hydroxybenzoic acids and some other phenolic acids are accepted by the enzyme, yielding products …”