- MICROORGANISMS FOR PRODUCING 4C-5C COMPOUNDS WITH UNSATURATION AND METHODS RELATED THERETO
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The invention provides a non-naturally occurring microbial organism having a butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol, pathway. The microbial organism contains at least one exogenous nucleic acid encoding an enzyme in a pathway. The invention additionally provides a method for producing butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol,. The method can include culturing a butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol-producing microbial organism, where the microbial organism expresses at least one exogenous nucleic acid encoding a pathway enzyme in a sufficient amount, and under conditions and for a sufficient period of time to produce butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol.
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Paragraph 0015; 00101
(2016/01/25)
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- Metabolism of 4-amino-3-hydroxybenzoic acid by Bordetella sp. strain 10d: A different modified meta-cleavage pathway for 2-aminophenols
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Bordetella sp. strain 10d metabolizes 4-amino-3-hydroxybenzoic acid via 2-hydroxymuconic 6-semialdehyde. Cell extracts from 4-amino-3-hydroxybenzoate- grown cells showed high NAD+-dependent 2-hydroxymuconic 6-semialdehyde dehydrogenase, 4-oxalocrotonate tautomerase, 4-oxalocrotonate decarboxylase, and 2-oxopent-4-enoate hydratase activities, but no 2-hydroxymuconic 6-semialdehyde hydrolase activity. These enzymes involved in 4-amino-3-hydroxybenzoate metabolism were purified and characterized. When 2-hydroxymuconic 6-semialdehyde was used as substrate in a reaction mixture containing NAD+ and cell extracts from 4-amino-3-hydroxybenzoate-grown cells, 4-oxalocrotonic acid, 2-oxopent-4-enoic acid, and 4-hydroxy-2-oxovaleric acid were identified as intermediates, and pyruvic acid was identified as the final product. A complete pathway for the metabolism of 4-amino-3-hydroxybenzoic acid in strain 10d is proposed. Strain 10d metabolized 2-hydroxymuconic 6-semialdehyde derived from 4-amino-3-hydroxybenzoic acid via a dehydrogenative route, not via a hydrolytic route. This proposed metabolic pathway differs considerably from the modified meta-cleavage pathway of 2-aminophenol and those previously reported for methyl- and chloroderivatives.
- Orii, Chika,Takenaka, Shinji,Murakami, Shuichiro,Aoki, Kenji
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p. 2653 - 2661
(2007/10/03)
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- The contribution of the substrate's carboxylate group to the mechanism of 4-oxalocrotonate tautomerase
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4-Oxalocrotonate tautomerase (4-OT) converts 2-oxo-4E-hexenedioate (1) to 2-oxo-3E-hexenedioate (3) through the dienol intermediate, 2-hydroxy-2,4- hexadiene-1,6-dioate (2). Previous studies established that the isomerization of 1 to 3 is primarily a suprafacial process. It was also suggested that the 6-carboxylate group of the substrate maintains the regio- and stereochemical fidelity of the reaction by anchoring the substrate at the active site. A subsequent study suggested an additional role for the 6-carboxylate group in the mechanism: the enzyme may utilize the binding energy of the carboxylate group to facilitate catalysis. In order to explore the role of the carboxylate group in the mechanism further, the nonenzymatic ratee constants for mono- and dicarboxylated substrates were measured and compared to the rates obtained for the corresponding enzymatic reactions. The results show that the missing carboxylate group has a profound effect on enzymatic catalysis as evidenced by the significant decreases (a 104- and a 105-fold reduction) in the values of k(cat)/K(m) observed for the two monocarboxylated substrates. A comparison of the noneeenzymatic rate constants indicates that the reduced k(cat)/K(m) values cannot be explained on the basis of the chemical reactivities. The stereochemical course of the 4-OT-catalyzed reaction was also determined using 2-hydroxy-2,4Z-heptadiene-1,7-dioate. The stereochemical analysis reveals that the presence of the carboxylate group improves the stereoselectivity of the enzyme-catalyzed ketonization of 2- hydroxy-2,4Z-heptadiene-1,7-dioate to 2-oxo-[3-2H]-4Z-heptene-1,7-dioate in 2H2O - a result that is consistent with its previously assignned role. These findings provide further evidence that the substrate's carboxylate group contributes to the mechanism of the enzyme in two ways: it anchors the substrate at the active site and it facilitates catalysis by destabilizing the substrate or by stabilizing the transition state.
- Lian, Huiling,Czerwinski, Robert M.,Stanley, Thanuja M.,Johnson Jr., William H.,Watson, Robert J.,Whitman, Christian P.
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p. 141 - 156
(2007/10/03)
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- Chemical and biochemical properties of 2-hydroxypentadienoic acid, a homologue of enolpyruvic acid
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2-Hydroxypentadienoic acid is shown to be a biochemical intermediate on the phenylpropionate catabolic pathway of Escherichia coli; its stability and ketonisation behaviour are compared with those of its homologue, enolpyruvate.
- Pollard, John R.,Henderson, Ian M. J.,Bugg, Timothy D. H.
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p. 1885 - 1886
(2007/10/03)
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- Dehalogenation and Deamination of L-2-Amino-4-chloro-4-pentenoic Acid by Proteus mirabilis
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Eighty-one strains of bacteria were tested for their ability to catalyze the release of chloride ion from DL-2-amino-4-chloro-4-pentenoic acid.A dehalogenating enzyme was obtained from the cells of Proteus mirablis IFO 3849, which can use the L-isomer.The enzyme was constitutively produced.The conversion of L-2-amino-4-chloro-4-pentenoic acid to 2-keto-4-pentenoic acid, ammonia, and chloride ion was demonstrated.The reaction product, 2-keto-4-pentenoic acid, was isolated as its 2,4-dinitrophenylhydrazone and identified by catalytic hydrogenolysis of the hydrazone to the corresponding amino acid, norvaline.
- Moriguchi, Mitsuaki,Hoshino, Seiichi,Hatanaka, Shin-Ichi
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p. 3295 - 3300
(2007/10/02)
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