Kinetic studies on chorismate mutase-prephenate dehydrogenase from Escherichia coli: models for the feedback inhibition of prephenate dehydrogenase by L-tyrosine

Biochemistry ◽  
1991 ◽  
Vol 30 (31) ◽  
pp. 7783-7788 ◽  
Author(s):  
Joanne Turnbull ◽  
John F. Morrison ◽  
W. W. Cleland
Keyword(s):  
Escherichia Coli ◽  
Feedback Inhibition ◽  
Kinetic Studies ◽  
Chorismate Mutase ◽  
Prephenate Dehydrogenase

scholarly journals Feedback Inhibition of Chorismate Mutase/Prephenate Dehydrogenase (TyrA) of Escherichia coli: Generation and Characterization of Tyrosine-Insensitive Mutants

2005 ◽  
Vol 71 (11) ◽  
pp. 7224-7228 ◽  
Author(s):  
Tina Lütke-Eversloh ◽  
Gregory Stephanopoulos
Keyword(s):  
Escherichia Coli ◽  
Dna Sequences ◽  
Molecular Level ◽  
Feedback Inhibition ◽  
Feedback Regulation ◽  
The Other ◽  
Chorismate Mutase ◽  
Amino Acid Substitutions ◽  
Prephenate Dehydrogenase

ABSTRACT In order to get insights into the feedback regulation by tyrosine of the Escherichia coli chorismate mutase/prephenate dehydrogenase (CM/PDH), which is encoded by the tyrA gene, feedback-inhibition-resistant (fbr) mutants were generated by error-prone PCR. The tyrA fbr mutants were selected by virtue of their resistance toward m-fluoro-d,l-tyrosine, and seven representatives were characterized on the biochemical as well as on the molecular level. The PDH activities of the purified His6-tagged TyrA proteins exhibited up to 35% of the enzyme activity of TyrAWT, but tyrosine did not inhibit the mutant PDH activities. On the other hand, CM activities of the TyrAfbr mutants were similar to those of the TyrAWT protein. Analyses of the DNA sequences of the tyrA genes revealed that tyrA fbr contained amino acid substitutions either at Tyr263 or at residues 354 to 357, indicating that these two sites are involved in the feedback inhibition by tyrosine.

scholarly journals 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

2008 ◽  
Vol 74 (10) ◽  
pp. 3284-3290 ◽  
Author(s):  
María I. Chávez-Béjar ◽  
Alvaro R. Lara ◽  
Hezraí López ◽  
Georgina Hernández-Chávez ◽  
Alfredo Martinez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Metabolic Engineering ◽  
Zymomonas Mobilis ◽  
Feedback Inhibition ◽  
Chorismate Mutase ◽  
Prephenate Dehydratase ◽  
E Coli ◽  
Prephenate Dehydrogenase ◽  
Expression Of Genes ◽  
Engineering Strategy

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 (PheACM) from Escherichia coli was compared to the expression of native feedback inhibition-sensitive chorismate mutase-prephenate dehydrogenase (CM-TyrAp) 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-TyrAp. In bioreactor experiments, a strain expressing both TyrC and PheACM 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.

pH Dependency of the reactions catalyzed by chorismate mutase-prephenate dehydrogenase from Escherichia coli

Biochemistry ◽  
1991 ◽  
Vol 30 (31) ◽  
pp. 7777-7782 ◽  
Author(s):  
Joanne Turnbull ◽  
W. W. Cleland ◽  
John F. Morrison
Keyword(s):  
Escherichia Coli ◽  
Chorismate Mutase ◽  
Prephenate Dehydrogenase ◽  
Ph Dependency
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