scholarly journals Catabolite Repression Control by Crc in 2xYT Medium Is Mediated by Posttranscriptional Regulation of bkdR Expression in Pseudomonas putida

2000 ◽  
Vol 182 (4) ◽  
pp. 1150-1153 ◽  
Author(s):  
Kathryn L. Hester ◽  
K. T. Madhusudhan ◽  
John R. Sokatch
Keyword(s):  
Pseudomonas Putida ◽  
Catabolite Repression ◽  
Posttranscriptional Regulation ◽  
Keto Acid ◽  
Wild Type ◽  
Transcript Levels ◽  
Acid Dehydrogenase ◽  
Rich Media ◽  
Branched Chain ◽  
Control Protein

ABSTRACT The effect of growth in 2xYT medium on catabolite repression control in Pseudomonas putida has been investigated using the bkd operon, encoding branched-chain keto acid dehydrogenase. Crc (catabolite repression control protein) was shown to be responsible for repression of bkd operon transcription in 2xYT. BkdR levels were elevated in a P. putida crcmutant, but bkdR transcript levels were the same in both wild type and crc mutant. This suggests that the mechanism of catabolite repression control in rich media by Crc involves posttranscriptional regulation of the bkdR message.

scholarly journals Crc Is Involved in Catabolite Repression Control of the bkd Operons of Pseudomonas putida andPseudomonas aeruginosa

2000 ◽  
Vol 182 (4) ◽  
pp. 1144-1149 ◽  
Author(s):  
Kathryn L. Hester ◽  
Jodi Lehman ◽  
Fares Najar ◽  
Lin Song ◽  
Bruce A. Roe ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Catabolite Repression ◽  
Carbon Sources ◽  
Keto Acid ◽  
Carbon Regulation ◽  
Acid Dehydrogenase ◽  
Transposon Mutants ◽  
Branched Chain ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT Crc (catabolite repression control) protein of Pseudomonas aeruginosa has shown to be involved in carbon regulation of several pathways. In this study, the role of Crc in catabolite repression control has been studied in Pseudomonas putida. The bkd operons of P. putida and P. aeruginosa encode the inducible multienzyme complex branched-chain keto acid dehydrogenase, which is regulated in both species by catabolite repression. We report here that this effect is mediated in both species by Crc. A 13-kb cloned DNA fragment containing the P. putida crc gene region was sequenced. Crc regulates the expression of branched-chain keto acid dehydrogenase, glucose-6-phosphate dehydrogenase, and amidase in both species but not urocanase, although the carbon sources responsible for catabolite repression in the two species differ. Transposon mutants affected in their expression of BkdR, the transcriptional activator of thebkd operon, were isolated and identified as crcand vacB (rnr) mutants. These mutants suggested that catabolite repression in pseudomonads might, in part, involve control of BkdR levels.

scholarly journals Molecular cloning of genes encoding branched-chain keto acid dehydrogenase of Pseudomonas putida.

1987 ◽  
Vol 169 (4) ◽  
pp. 1619-1625 ◽  
Author(s):  
P J Sykes ◽  
G Burns ◽  
J Menard ◽  
K Hatter ◽  
J R Sokatch
Keyword(s):  
Pseudomonas Putida ◽  
Molecular Cloning ◽  
Keto Acid ◽  
Acid Dehydrogenase ◽  
Genes Encoding ◽  
Branched Chain

scholarly journals Insertional Inactivation of Branched-Chain α-Keto Acid Dehydrogenase in Staphylococcus aureus Leads to Decreased Branched-Chain Membrane Fatty Acid Content and Increased Susceptibility to Certain Stresses

2008 ◽  
Vol 74 (19) ◽  
pp. 5882-5890 ◽  
Author(s):  
Vineet K. Singh ◽  
Dipti S. Hattangady ◽  
Efstathios S. Giotis ◽  
Atul K. Singh ◽  
Neal R. Chamberlain ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Fatty Acid ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Stress Conditions ◽  
Enzyme Complex ◽  
Keto Acid ◽  
Wild Type ◽  
Acid Dehydrogenase ◽  
Branched Chain

ABSTRACT Staphylococcus aureus is a major community and nosocomial pathogen. Its ability to withstand multiple stress conditions and quickly develop resistance to antibiotics complicates the control of staphylococcal infections. Adaptation to lower temperatures is a key for the survival of bacterial species outside the host. Branched-chain α-keto acid dehydrogenase (BKD) is an enzyme complex that catalyzes the early stages of branched-chain fatty acid (BCFA) production. In this study, BKD was inactivated, resulting in reduced levels of BCFAs in the membrane of S. aureus. Growth of the BKD-inactivated mutant was progressively more impaired than that of wild-type S. aureus with decreasing temperature, to the point that the mutant could not grow at 12�C. The growth of the mutant was markedly stimulated by the inclusion of 2-methylbutyrate in the growth medium at all temperatures tested. 2-Methylbutyrate is a precursor of odd-numbered anteiso fatty acids and bypasses BKD. Interestingly, growth of wild-type S. aureus was also stimulated by including 2-methylbutyrate in the medium, especially at lower temperatures. The anteiso fatty acid content of the BKD-inactivated mutant was restored by the inclusion of 2-methylbutyrate in the medium. Fluorescence polarization measurements indicated that the membrane of the BKD-inactivated mutant was significantly less fluid than that of wild-type S. aureus. Consistent with this result, the mutant showed decreased toluene tolerance that could be increased by the inclusion of 2-methylbutyrate in the medium. The BKD-inactivated mutant was more susceptible to alkaline pH and oxidative stress conditions. Inactivation of the BKD enzyme complex in S. aureus also led to a reduction in adherence of the mutant to eukaryotic cells and its survival in a mouse host. In addition, the mutant offers a tool to study the role of membrane fluidity in the interaction of S. aureus with antimicrobial substances.

scholarly journals Purification of a branched-chain keto acid dehydrogenase from Pseudomonas putida.

1981 ◽  
Vol 148 (2) ◽  
pp. 647-652 ◽  
Author(s):  
J R Sokatch ◽  
V McCully ◽  
C M Roberts
Keyword(s):  
Pseudomonas Putida ◽  
Keto Acid ◽  
Acid Dehydrogenase ◽  
Branched Chain
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