Cloning and sequences of the first eight genes of the chromosomally encoded (methyl) phenol degradation pathway from Pseudomonas putida P35X

Gene ◽  
1994 ◽  
Vol 151 (1-2) ◽  
pp. 29-36 ◽  
Author(s):  
Lee Ching Ng ◽  
Victoria Shingle ◽  
Chun Chau Sze ◽  
Chit Laa Poh
Keyword(s):  
Pseudomonas Putida ◽  
Phenol Degradation ◽  
Degradation Pathway

scholarly journals Levels and Activity of the Pseudomonas putida Global Regulatory Protein Crc Vary According to Growth Conditions

2005 ◽  
Vol 187 (11) ◽  
pp. 3678-3686 ◽  
Author(s):  
Ana Ruiz-Manzano ◽  
Luis Yuste ◽  
Fernando Rojo
Keyword(s):  
Pseudomonas Putida ◽  
Regulatory Protein ◽  
Carbon Sources ◽  
Signal Transduction Pathway ◽  
Growth Conditions ◽  
Degradation Pathway ◽  
Complete Medium ◽  
Alkane Degradation ◽  
Mutant Proteins ◽  
Catalytic Sites

ABSTRACT The global regulatory protein Crc is involved in the repression of several catabolic pathways for sugars, hydrocarbons, and nitrogenated and aromatic compounds in Pseudomonas putida and Pseudomonas aeruginosa when other preferred carbon sources are present in the culture medium (catabolite repression), therefore modulating carbon metabolism. We have analyzed whether the levels or the activity of Crc is regulated. Crc activity was followed by its ability to inhibit the induction by alkanes of the P. putida OCT plasmid alkane degradation pathway when cells grow in a complete medium, where the effect of Crc is very strong. The abundance of crc transcripts and the amounts of Crc protein were higher under repressing conditions than under nonrepressing conditions. The presence of crc on a high-copy-number plasmid considerably increased Crc levels, but this impaired its ability to inhibit the alkane degradation pathway. Crc shows similarity to a family of nucleases that have highly conserved residues at their catalytic sites. Mutation of the corresponding residues in Crc (Asp220 and His246) led to proteins that can inhibit induction of the alkane degradation pathway when present at normal or elevated levels in the cell. Repression by these mutant proteins occurred only under repressing conditions. These results suggest that both the amounts and the activity of Crc are modulated and support previous proposals that Crc may form part of a signal transduction pathway. Furthermore, the activity of the mutant proteins suggests that Crc is not a nuclease.

scholarly journals The Target for the Pseudomonas putida Crc Global Regulator in the Benzoate Degradation Pathway Is the BenR Transcriptional Regulator

2007 ◽  
Vol 190 (5) ◽  
pp. 1539-1545 ◽  
Author(s):  
Renata Moreno ◽  
Fernando Rojo
Keyword(s):  
Pseudomonas Putida ◽  
Target Genes ◽  
Carbon Sources ◽  
Degradation Pathway ◽  
Complete Medium ◽  
Mrna Levels ◽  
Global Regulator ◽  
Benzoate Degradation ◽  
Transcriptional Units ◽  
Degradation Intermediates

ABSTRACT Crc protein is a global regulator involved in catabolite repression control of several pathways for the assimilation of carbon sources in pseudomonads when other preferred substrates are present. In Pseudomonas putida cells growing exponentially in a complete medium containing benzoate, Crc strongly inhibits the expression of the benzoate degradation genes. These genes are organized into several transcriptional units. We show that Crc directly inhibits the expression of the peripheral genes that transform benzoate into catechol (the ben genes) but that its effect on genes corresponding to further steps of the pathway (the cat and pca genes of the central catechol and β-ketoadipate pathways) is indirect, since these genes are not induced because the degradation intermediates, which act as inducers, are not produced. Crc inhibits the translation of target genes by binding to mRNA. The expression of the ben, cat, and pca genes requires the BenR, CatR, and PcaR transcriptional activators, respectively. Crc significantly reduced benABCD mRNA levels but did not affect those of benR. Crc bound to the 5′ end of benR mRNA but not to equivalent regions of catR and pcaR mRNAs. A translational fusion of the benR and lacZ genes was sensitive to Crc, but a transcriptional fusion was not. We propose that Crc acts by reducing the translation of benR mRNA, decreasing BenR levels below those required for the full expression of the benABCD genes. This strategy provides great metabolic flexibility, allowing the hierarchical assimilation of different structurally related compounds that share a common central pathway by selectively regulating the entry of each substrate into the central pathway.

scholarly journals Different Spectra of Stationary-Phase Mutations in Early-Arising versus Late-Arising Mutants of Pseudomonas putida: Involvement of the DNA Repair Enzyme MutY and the Stationary-Phase Sigma Factor RpoS

2002 ◽  
Vol 184 (24) ◽  
pp. 6957-6965 ◽  
Author(s):  
Signe Saumaa ◽  
Andres Tover ◽  
Lagle Kasak ◽  
Maia Kivisaar
Keyword(s):  
Stationary Phase ◽  
Pseudomonas Putida ◽  
Transcriptional Activation ◽  
Sigma Factor ◽  
Phenol Degradation ◽  
Test System ◽  
Growth Barriers ◽  
Mutational Processes ◽  
Sigma Factor Rpos ◽  
Selection Of

ABSTRACT Stationary-phase mutations occur in populations of stressed, nongrowing, and slowly growing cells and allow mutant bacteria to overcome growth barriers. Mutational processes in starving cells are different from those occurring in growing bacteria. Here, we present evidence that changes in mutational processes also take place during starvation of bacteria. Our test system for selection of mutants based on creation of functional promoters for the transcriptional activation of the phenol degradation genes pheBA in starving Pseudomonas putida enables us to study base substitutions (C-to-A or G-to-T transversions), deletions, and insertions. We observed changes in the spectrum of promoter-creating mutations during prolonged starvation of Pseudomonas putida on phenol minimal plates. One particular C-to-A transversion was the prevailing mutation in starving cells. However, with increasing time of starvation, the importance of this mutation decreased but the percentage of other types of mutations, such as 2- to 3-bp deletions, increased. The rate of transversions was markedly elevated in the P. putida MutY-defective strain. The occurrence of 2- to 3-bp deletions required the stationary-phase sigma factor RpoS, which indicates that some mutagenic pathway is positively controlled by RpoS in P. putida.

scholarly journals Expression of the Pseudomonas putida OCT Plasmid Alkane Degradation Pathway Is Modulated by Two Different Global Control Signals: Evidence from Continuous Cultures

2003 ◽  
Vol 185 (16) ◽  
pp. 4772-4778 ◽  
Author(s):  
M. Alejandro Dinamarca ◽  
Isabel Aranda-Olmedo ◽  
Antonio Puyet ◽  
Fernando Rojo
Keyword(s):  
Carbon Source ◽  
Pseudomonas Putida ◽  
Catabolite Repression ◽  
Degradation Pathway ◽  
Independent Effect ◽  
Physiological Status ◽  
Carbon Limitation ◽  
Alkane Degradation ◽  
Global Control ◽  
Ubiquinol Oxidase

ABSTRACT Expression of the genes of the alkane degradation pathway encoded in the Pseudomonas putida OCT plasmid are subject to negative and dominant global control depending on the carbon source used and on the physiological status of the cell. We investigated the signals responsible for this control in chemostat cultures under conditions of nutrient or oxygen limitation. Our results show that this global control is not related to the growth rate and responds to two different signals. One signal is the concentration of the carbon source that generates the repressing effect (true catabolite repression control). The second signal is influenced by the level of expression of the cytochome o ubiquinol oxidase, which in turn depends on factors such as oxygen availability or the carbon source used. Since under carbon limitation conditions the first signal is relieved but the second signal is not, we propose that modulation mediated by the cytochrome o ubiquinol oxidase is not classical catabolite repression control but rather a more general physiological control mechanism. The two signals have an additive, but independent, effect, inhibiting induction of the alkane degradation pathway.

Bio-production of high-purity propionate by engineering l-threonine degradation pathway in Pseudomonas putida

2020 ◽  
Vol 104 (12) ◽  
pp. 5303-5313 ◽  
Author(s):  
Chao Ma ◽  
Qingxuan Mu ◽  
Lei Wang ◽  
Yanan Shi ◽  
Lingfeng Zhu ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
High Purity ◽  
Degradation Pathway

scholarly journals Physiological changes of Candida tropicalis population degrading phenol in fed batch reactor

2003 ◽  
Vol 46 (4) ◽  
pp. 537-543 ◽  
Author(s):  
Eliska Komarkova ◽  
Jan Paca ◽  
Eva Klapkova ◽  
Marie Stiborova ◽  
Carlos R Soccol ◽  
...  
Keyword(s):  
Candida Tropicalis ◽  
Batch Reactor ◽  
Phenol Degradation ◽  
Degradation Pathway ◽  
Product Inhibition ◽  
Endogenous Respiration ◽  
Starvation Stress ◽  
Fed Batch ◽  
Respiration Activity ◽  
Key Enzyme

Candida tropicalis can use phenol as the sole carbon and energy source. Experiments regarding phenol degradations from the water phase were carried out. The fermentor was operated as a fed-batch system with oxistat control. Under conditions of nutrient limitation and an excess of oxygen the respiration activity of cells was suppressed and some color metabolites (black-brown) started to be formed. An accumulation of these products inhibited the cell growth under aerobic conditions. Another impact was a decrease of the phenol hydroxylase activity as the key enzyme of the phenol degradation pathway at the end of the cell respiration activity. This decrease is linked with the above mentioned product inhibition. The cell death studied by fluorescent probe proceeded very slowly after the loss of the respiration activity. The starvation stress induced an increase of the endogenous respiration rate at the expense of phenol oxidation.

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