Organization and control of genes encoding catabolic enzymes in Rhizobiaceae
Rhizobiaceae, a diverse bacterial group comprising rhizobia and agrobacteria, symbiotic partnership with plants form nitrogen-fixing nodules on plant roots or are plant pathogens. Phenolic compounds produced by plants serve as inducers of rhizobial nodulation genes and agrobacterial virulence genes reflect their capacity to utilize numerous aromatics, including phenolics, as a source of carbon and energy. In many microbes the aerobic degradation of numerous aromatic compounds to tricarboxylic acid cycle intermediates is achieved by the [beta]-ketoadipate pathway. Our initial studies focused on the organization and regulation of the ketoadipate pathway in Agrobacterium tumefaciens. We have cloned, identified and characterized a novel regulatory gene that modulates expression of an adjacent pca (protocatechuate) structural gene, pcaD. Regulation of pcaD is mediated by the regulatory gene, termed pcaQ, in concert with the intermediate [beta]-carboxy-cis,cis-muconate. [beta]-carboxy-cis,cismuconate is an unstable chemical, not marketed commercially, and it is unlikely to permeate Escherichia coli cells if supplied in media. Because of these factors, characterization of pcaQ in E. coli required an in vivo delivery system for [beta]-carboxycis,cis-muconate. This was accomplished by designing an E. coli strain that expressed an Acinetobacter calcoaceticus pcaA gene for conversion of protocatechuate to [beta]-carboxy-cis,cis-muconate.
- Research Organization:
- Yale Univ., New Haven, CT (United States). Dept. of Biology
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-88ER13947
- OSTI ID:
- 6754773
- Report Number(s):
- DOE/ER/13947-4; ON: DE93010353
- Country of Publication:
- United States
- Language:
- English
Similar Records
Regulation of phenolic catabolism in Rhizobium leguminosarum biovar trifolii
Stereochemistry of 4-carboxymuconolactone decarboxylase and muconolactone isomerase in the. beta. -ketoadipate pathway
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
GENE OPERONS
DNA-CLONING
PHENOLS
BIODEGRADATION
RHIZOBIUM
MOLECULAR BIOLOGY
BIOLOGICAL PATHWAYS
CATABOLISM
GENE REGULATION
GENES
PROGRESS REPORT
AROMATICS
BACTERIA
CHEMICAL REACTIONS
CLONING
DECOMPOSITION
DNA HYBRIDIZATION
DOCUMENT TYPES
HYBRIDIZATION
HYDROXY COMPOUNDS
METABOLISM
MICROORGANISMS
ORGANIC COMPOUNDS
090900* - Biomass Fuels- Processing- (1990-)
550200 - Biochemistry
550500 - Metabolism
550400 - Genetics
553000 - Agriculture & Food Technology