Comparative Analysis of Catabolic and Anabolic Dehydroshikimate Dehydratases for 3,4-DHBA Production in Escherichia coli

• Published in: Microorganisms (Basel) 2022-07, Vol.10 (7), p.1357
• Main Authors: Shmonova, Ekaterina A., Savrasova, Ekaterina A., Fedorova, Elizaveta N., Doroshenko, Vera G.
• Format: Article
• Language: English
• Subjects: 3,4-DHBA; Acids; Bacteria; Biosynthesis; Comparative analysis; Dehydration; dehydroshikimate dehydratase; Dihydroxybenzoic acid; DNA polymerase; E coli; Enzymes; Escherichia coli; Fermentation; microbial production; Microorganisms; Neurospora; Plasmids; Product inhibition; Proteins; protocatechuic acid
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms10071357

The production of 3,4-dihydroxybenzoic acid (3,4-DHBA or protocatechuate) is a relevant task owing to 3,4-DHBA’s pharmaceutical properties and its use as a precursor for subsequent synthesis of high value-added chemicals. The microbial production of 3,4-DHBA using dehydroshikimate dehydratase (DSD) (EC: 4.2.1.118) has been demonstrated previously. DSDs from soil-dwelling organisms (where DSD is involved in quinate/shikimate degradation) and from Bacillus spp. (synthesizing the 3,4-DHBA-containing siderophore) were compared in terms of the kinetic properties and their ability to produce 3,4-DHBA. Catabolic DSDs from Corynebacterium glutamicum (QsuB) and Neurospora crassa (Qa-4) had higher Km (1 and 0.6 mM, respectively) and kcat (61 and 220 s−1, respectively) than biosynthetic AsbF from Bacillus thuringiensis (Km~0.04 mM, kcat~1 s−1). Product inhibition was found to be a crucial factor when choosing DSD for strain development. AsbF was more inhibited by 3,4-DHBA (IC50~0.08 mM), and Escherichia coli MG1655 ΔaroE PlacUV5-asbFattφ80 strain provided only 0.2 g/L 3,4-DHBA in test-tube fermentation. Isogenic strains MG1655 ΔaroE PlacUV5-qsuBattφ80 and MG1655 ΔaroE PlacUV5-qa-4attφ80 expressing QsuB and Qa-4 with IC50 ~0.35 mM and ~0.64 mM, respectively, accumulated 2.7 g/L 3,4-DHBA under the same conditions.