Shikimate Pathway and Aromatic Amino Acid Biosynthesis

Abstract

The shikimate pathway consists of seven enzymatic reactions whose end product chorismate is the precursor for the synthesis of the aromatic amino acids Phe, Tyr and Trp. In fungi and plants, chorismate is a precursor for many specialised metabolites (i.e. secondary metabolites) that play an important role in the plant's interaction with its environment. The shikimate pathway and aromatic amino acid biosynthesis have been extensively studied in a variety of microorganisms, fungi and plants. Furthermore, the dual involvement of the shikimate and aromatic amino acid biosynthesis pathways in central and specialised metabolism still raises major questions regarding the genes and enzymes involved, and their control, their evolutionary origins and coordinated regulation with genes of associated pathways in response to altered environmental conditions and diverse developmental programs. Key Concepts: The shikimate pathway is the only known pathway for biosynthesis of chorismate and the aromatic amino acids Phe, Tyr and Trp. The shikimate pathway is a bridge between central metabolism and specialised metabolism. The shikimate pathway occurs in various groups of microorganisms, plants and parasites, whereas it does not occur in animals. The pathway enzymes are being targeted for antimicrobial drug and herbicide design. Shikimic acid is an essential metabolite that may balance the metabolic status of the pathway. Chorismate is a branch point metabolite for aromatic amino acids and phenolic compounds. This is an ancient eukaryotic pathway which has been subject to diverse evolutionary processes. Several enzymes from these pathways are allosterically regulated by their end products: Phe, Tyr or Trp. The shikimate pathway and aromatic amino acids, and the specialised metabolites derived from them, simultaneously respond to rhythmic changes.

Host Transcriptional Response of Sclerotinia sclerotiorum Induced by the Mycoparasite Coniothyrium minitans

“…Shikimate pathway is also important for development and pathogenicity in fungi. Seven enzymes participating in the pathway were usually designed as antimicrobial and antiparasitic drug targets (Roberts et al, 1998;Keeling et al, 1999;Aditya et al, 2012;Tzin et al, 2012;Mir et al, 2015). The chorismate mutase Cmu1 secreted by Ustilago maydis was a virulence factor and deletion mutants of the gene led to virulence attenuation on maize, with correspondingly up-regulated during biotrophic development of U. maydis (Djamei et al, 2011).…”

Mycobacterium tuberculosis Shikimate Pathway Enzymes as Targets for the Rational Design of Anti-Tuberculosis Drugs

“…The first component enzyme in the shikimate pathway (Figure 1), 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (DAHPS), catalyzes the first committed step in the biosynthesis of aromatic compounds in plants and microorganisms. This enzyme is responsible for an aldol condensation reaction between PEP and E4P to produce 3-deoxy-d-arabino-heptulosonate 7-phosphate (DAHP) and inorganic phosphate [24,25]. DAHPS enzymes are currently classified into two distinct families-type I and type II-based on their amino acid sequence and molecular mass.…”

“…(c) Natural occurring molecule (Narigin) found by virtual screening by Lone and coworkers [81].2.4. Shikimate 5-Dehydrogenase (aroE Coding Sequence; EC 1.1.1 25).…”

Bioprocess Optimization for the Production of Aromatic Compounds With Metabolically Engineered Hosts: Recent Developments and Future Challenges

“…The reactions are catalyzed by prephenate dehydratase (PDT) and prephenate dehydrogenase (PDH), respectively. The last step comprises the transamination of PPY to L-Phe and of 4-HPP to L-Tyr that is catalyzed by an aminotransferase (AT) (Tzin et al, 2001; Figure 1). The pathway for L-Trp production from CHO requires six steps.…”