scholarly journals The Enigmatic Escherichia coli fadE Gene Is yafH

2002 ◽  
Vol 184 (13) ◽  
pp. 3759-3764 ◽  
Author(s):  
John W. Campbell ◽  
John E. Cronan
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Regulatory Protein ◽  
Gene Encoding ◽  
Experimental Proof ◽  
Fatty Acid Degradation ◽  
Acid Degradation ◽  
Genome Array ◽  
Acyl Coenzyme A ◽  
Array Analyses

ABSTRACT The identity of the gene encoding acyl coenzyme A dehydrogenase is a major remaining mystery of the Escherichia coli fatty acid degradation (fad) regulon. Our prior genome array analyses showed that transcription of the yafH gene is controlled by the FadR regulatory protein. We now report direct experimental proof that yafH and fadE are the same gene.

Photocatalytic inactivation of Escherichia coli—The roles of genes in β-oxidation of fatty acid degradation

2016 ◽  
Vol 266 ◽  
pp. 219-225 ◽  
Author(s):  
Ka Him Chu ◽  
Guocheng Huang ◽  
Taicheng An ◽  
Guiying Li ◽  
Pui Ling Yip ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Fatty Acid Degradation ◽  
Acid Degradation ◽  
Photocatalytic Inactivation

scholarly journals The β-Oxidation Systems of Escherichia coli and Salmonella enterica Are Not Functionally Equivalent

2006 ◽  
Vol 188 (2) ◽  
pp. 599-608 ◽  
Author(s):  
Surtaj Hussain Iram ◽  
John E. Cronan
Keyword(s):  
Escherichia Coli ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Octanoic Acid ◽  
Decanoic Acid ◽  
Wild Type ◽  
Fatty Acid Degradation ◽  
E Coli ◽  
Acid Degradation ◽  
Type Strains

ABSTRACT Based on its genome sequence, the pathway of β-oxidative fatty acid degradation in Salmonella enterica serovar Typhimurium LT2 has been thought to be identical to the well-characterized Escherichia coli K-12 system. We report that wild-type strains of S. enterica grow on decanoic acid, whereas wild-type E. coli strains cannot. Mutant strains (carrying fadR) of both organisms in which the genes of fatty acid degradation (fad) are expressed constitutively are readily isolated. The S. enterica fadR strains grow more rapidly than the wild-type strains on decanoic acid and also grow well on octanoic and hexanoic acids (which do not support growth of wild-type strains). By contrast, E. coli fadR strains grow well on decanoic acid but grow only exceedingly slowly on octanoic acid and fail to grow at all on hexanoic acid. The two wild-type organisms also differed in the ability to grow on oleic acid when FadR was overexpressed. Under these superrepression conditions, E. coli failed to grow, whereas S. enterica grew well. Exchange of the wild-type fadR genes between the two organisms showed this to be a property of S. enterica rather than of the FadR proteins per se. This difference in growth was attributed to S. enterica having higher cytosolic levels of the inducing ligands, long-chain acyl coenzyme As (acyl-CoAs). The most striking results were the differences in the compositions of CoA metabolites of strains grown with octanoic acid or oleic acid. S. enterica cleanly converted all of the acid to acetyl-CoA, whereas E. coli accumulated high levels of intermediate-chain-length products. Exchange of homologous genes between the two organisms showed that the S. enterica FadE and FadBA enzymes were responsible for the greater efficiency of β-oxidation relative to that of E. coli.

scholarly journals Expanded roles of pyruvate-sensing PdhR in transcription regulation of the Escherichia coli K-12 genome: fatty acid catabolism and cell motility

2020 ◽  
Vol 6 (10) ◽  
Author(s):  
Takumi Anzai ◽  
Sousuke Imamura ◽  
Akira Ishihama ◽  
Tomohiro Shimada
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid ◽  
Type Species ◽  
Metabolic Energy ◽  
Oxidative Decarboxylation ◽  
Fatty Acid Degradation ◽  
Content Type ◽  
Acid Degradation ◽  
Link Type ◽  
K 12

The transcription factor PdhR has been recognized as the master regulator of the pyruvate catabolism pathway in Escherichia coli , including both NAD-linked oxidative decarboxylation of pyruvate to acetyl-CoA by PDHc (pyruvate dehydrogenase complex) and respiratory electron transport of NADH to oxygen by Ndh-CyoABCD enzymes. To identify the whole set of regulatory targets under the control of pyruvate-sensing PdhR, we performed genomic SELEX (gSELEX) screening in vitro. A total of 35 PdhR-binding sites were identified along the E. coli K-12 genome, including previously identified targets. Possible involvement of PdhR in regulation of the newly identified target genes was analysed in detail by gel shift assay, RT-qPCR and Northern blot analysis. The results indicated the participation of PdhR in positive regulation of fatty acid degradation genes and negative regulation of cell mobility genes. In fact, GC analysis indicated an increase in free fatty acids in the mutant lacking PdhR. We propose that PdhR is a bifunctional global regulator for control of a total of 16–23 targets, including not only the genes involved in central carbon metabolism but also some genes for the surrounding pyruvate-sensing cellular pathways such as fatty acid degradation and flagella formation. The activity of PdhR is controlled by pyruvate, the key node between a wide variety of metabolic pathways, including generation of metabolic energy and cell building blocks.

Sign in / Sign up

Export Citation Format

Share Document