Importance of Shikimate Pathway

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What is the Shikimate Pathway?

  • The Shikimate pathway converts simple carbohydrates from glycolysis and the pentose phosphate pathway to aromatic amino acids.
  • A total of seven metabolic steps.
  • Forms 5-enolpyruvylshikmate-3-phosphate (EPSP) by combing the substrate-3-phosphate (S3P) and phosphoenolpyruvate (PEP).
    • Enzyme: 5-enolpyruvylshikimate-3-phosphate synthases (EPSPS)
  • The shikimate pathway is found only in microorganisms and plants, NOT animals.





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What's so Important of Aromatic Amino Acids?

  • Aromatic Amino Acids Produce:
    • Lignins
    • Alkaloids
    • Flavonoids
    • Benzoic Acids
    • Plant Hormones
    • Vitamins K and D
    • Amino Acids needed for protein synthesis




Flavonoids

EPSP Synthase

  • Major enzyme used in the shikimate Pathway
  • The gene encoding for EPSPS is found in the nucleus and the enzyme is found in the chloroplast.
  • The peptide sequence is 444 amino acids long, and a transit peptide sequence that is 72 amino acids long.
    • Transit peptide sequence transports the enzyme to the chloroplast.
    • The peptide sequence is then cleaved, once in the chloroplast.
  • Function is to combine the substrate shikimate-3-phosphate (SP3) with phosphoenolpyruvate (PEP) to form the product EPSP.



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EPSP Synthase Activity



Step 1: Binding S3P





Step 2: Binding PEP



Step 3: EPSP product produced

Animation:


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Last Update: December 16, 2009, at 09:13 AM

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