Construction of a synthetic metabolic pathway for the production of 2,4-dihydroxybutyric acid from homoserine.
Metab Eng
; 45: 237-245, 2018 01.
Article
em En
| MEDLINE
| ID: mdl-29248755
ABSTRACT
2,4-dihydroxybutyrate (DHB) is a precursor for the chemical synthesis of the methionine analogue 2-hydroxy-4-(methylthio)butyrate. Since no annotated metabolic pathway exists for its microbial production from sugar, we have conceived a two-step synthetic metabolic pathway which converts the natural amino acid homoserine to DHB. The pathway proceeds through the homoserine transaminase-catalyzed deamination of homoserine to obtain 2-oxo-4-hydroxybutyrate (OHB), and continues with the reduction of OHB to DHB, which is catalyzed by an OHB reductase enzyme. We identified homoserine transaminase and OHB reductase activity in several candidate enzymes which act on sterically cognate substrates, and improved OHB reductase activity of lactate dehydrogenase A of Lactococcus lactis by structure-based enzyme engineering. Fed-batch cultivation of a homoserine-overproducing Escherichia coli strain which expressed homoserine transaminase and OHB reductase enzymes resulted in the production of 5.3g/L DHB at a yield of 0.1g/g.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Butileno Glicóis
/
Butiratos
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Escherichia coli
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Engenharia Metabólica
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Homosserina
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article