title: Metabolic engineering of Escherichia coli for L-tyrosine production by expression of genes coding for the chorismate mutase domain of the native chorismate mutase-prephenate dehydratase and a cyclohexadienyl dehydrogenase from Zymomonas mobilis.
abstract: The expression of the feedback inhibition-insensitive enzyme cyclohexadienyl dehydrogenase (TyrC) from Zymomonas mobilis and the chorismate mutase domain from native chorismate mutase-prephenate dehydratase (PheA(CM)) from Escherichia coli was compared to the expression of native feedback inhibition-sensitive chorismate mutase-prephenate dehydrogenase (CM-TyrA(p)) with regard to the capacity to produce l-tyrosine in E. coli strains modified to increase the carbon flow to chorismate. Shake flask experiments showed that TyrC increased the yield of l-tyrosine from glucose (Y(l-Tyr/Glc)) by 6.8-fold compared to the yield obtained with CM-TyrA(p). In bioreactor experiments, a strain expressing both TyrC and PheA(CM) produced 3 g/liter of l-tyrosine with a Y(l-Tyr/Glc) of 66 mg/g. These values are 46 and 48% higher than the values for a strain expressing only TyrC. The results show that the feedback inhibition-insensitive enzymes can be employed for strain development as part of a metabolic engineering strategy for l-tyrosine production.
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos 62210, México.
authors.forename: María I
authors.initials: MI
authors.lastname: Chávez-Béjar
authors.forename: Alvaro R
authors.initials: AR
authors.lastname: Lara
authors.forename: Hezraí
authors.initials: H
authors.lastname: López
authors.forename: Georgina
authors.initials: G
authors.lastname: Hernández-Chávez
authors.forename: Alfredo
authors.initials: A
authors.lastname: Martinez
authors.forename: Octavio T
authors.initials: OT
authors.lastname: Ramírez
authors.forename: Francisco
authors.initials: F
authors.lastname: Bolívar
authors.forename: Guillermo
authors.initials: G
authors.lastname: Gosset
mesh_terms: D018533:Biomass; D019149:Bioreactors; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D010957:Plasmids; D011302:Prephenate Dehydratase / Q000235:genetics*; D011303:Prephenate Dehydrogenase / Q000235:genetics*; D014443:Tyrosine / Q000096:biosynthesis*; D017355:Zymomonas / Q000201:enzymology* / Q000235:genetics
chemical_list: D014443:Tyrosine; D011303:Prephenate Dehydrogenase; C027017:cyclohexadienyl dehydrogenase; D011302:Prephenate Dehydratase; D005947:Glucose