5-enolpyruvyl shikimate 3-phosphate synthase EPSPS

Aromatic Amino Acid Biosynthesis. The shikimate pathway is the biosynthetic route to the aromatic amino acids tryptophan, tyrosine and phenylalanine as well as a large number of secondary metabolites such as flavonoids, anthocyanins, auxins and alkaloids. One enzyme in this pathway is 5-enolpyruvyl shikimate-3-phosphate synthase (EPSP synthase) (Figure 2.9). 

Inhibits 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPS), an enzyme of the aromatic acid and biosynthesis pathway. This prevents synthesis of essential aromatic amino acids needed for protein biosynthesis... 

RR soybean was developed using a glyphosate insensitive CP4-EPSPS (5-enolpyruvyl shikimate 3-phosphate synthase). Since its introduction in 1996, RR soybean has increased steadily from 2 to 89% of the total soybean acres grown in 2005 (Fig. 6.1.2). The widespread adoption of RR soybeans has resulted in significant grower and environmental benefits. In 2004 alone, RR soybeans reduced grower production costs by 1.37 billion and pesticide use by 22.4 million pounds. Furthermore, there has been about a 64% increase in the number of no-till soybean acres that decreased soil erosion, dust and pesticide run-off, and improved soil moisture, air and water quality [2]. 

A number of analogues that mimic the intermediate formed during the EPSP nthase conversion of shikimic-3-phosphate into EPSP (5-enolpyruvyl shikimate-3-phosphate) have been prepared and tested as inhibitors of the enzyme. The best was shown to be 63. (Z)-3-Fluoro-phosphoenolpyruvate functions as a pseudosubstrate for EPSP synthase producing in one step the same adduct 63, but as an isomeric mixture. ... 

EPSP synthase catalyzes a rare type of reaction in which the intact enolpyruvyl (carboxyvinyl) group is transferred from phosphoenolpyruvate (PEP) to the 5-hydroxyl group of shikimate 3-phosphate (Fig. 6). This type of reaction is encountered in only one other known enz3rmatic process the transfer of the enolpyruvyl group to UDP-N-... 

Enolpyruvylshikimate-3-phosphate (EPSP) synthase (EC 2.5.1.19), also known as 3-phosphoshikimate 1-carboxyvinyltransferase, catalyzes the reversible transfer of the enolpyruvyl group from PEP to shikimate 3-phosphate (Figure 2.2). There is no known cofactor requirement. When purified to homogeneity, bacterial and plant EPSP synthases are monomeric monofunctional proteins of molecular weight 40,000-50,000. " Some fungi have a radically different molecular architecture in which EPSP synthase is part of a pentafunctional polypeptide which also contains the previous four enzymatic activities of the common shikimate pathway, the arom complex. 

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