Roles of the divergent branches of the meta-cleavage pathway in the degradation of benzoate and substituted benzoates.

Details

Serval ID
serval:BIB_5378A80C60A1
Type
Article: article from journal or magazin.
Collection
Publications
Title
Roles of the divergent branches of the meta-cleavage pathway in the degradation of benzoate and substituted benzoates.
Journal
Journal of Bacteriology
Author(s)
Harayama S., Mermod N., Rekik M., Lehrbach P.R., Timmis K.N.
ISSN
0021-9193[print], 0021-9193[linking]
Publication state
Published
Issued date
02/1987
Volume
169
Number
2
Pages
558-564
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
The TOL plasmid-specified meta-cleavage pathway for the oxidative catabolism of benzoate and toluates branches at the ring cleavage products of catechols and reconverges later at 2-oxopent-4-enoate or its corresponding substituted derivatives. The hydrolytic branch of the pathway involves the direct formation of 2-oxopent-4-enoate or its derivatives, whereas the oxalocrotonate branch involves three enzymatic steps effected by a dehydrogenase, an isomerase, and a decarboxylase, which produce the same compounds. Evidence is presented which shows that benzoate and p-toluate can, under certain circumstances, be catabolized by the hydrolytic branch. However, in a fully functional pathway, only m-toluate is dissimilated via this branch, and benzoate and p-toluate are catabolized almost exclusively by the oxalocrotonate branch. The biochemical basis of this selectivity was found to reside in the high affinity of the dehydrogenase for ring fission products derived from benzoate and p-toluate and its inability to attack the ring fission product derived from m-toluate. Although isomerization of 4-oxalocrotonate occurs spontaneously in vitro, enzymatic isomerization was found to be essential for effective functioning of this branch of the pathway in vivo.
Keywords
Benzoates/metabolism, Benzoic Acid, Escherichia coli/genetics, Escherichia coli/metabolism, Kinetics, Mutation, Phenotype, Plasmids, Species Specificity, Structure-Activity Relationship
Pubmed
Web of science
Create date
24/01/2008 11:41
Last modification date
20/08/2019 15:08
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