scholarly journals Fatty Acid Degradation in Escherichia coli. An Inducible System for the Uptake of Fatty Acids and Further Characterization of old Mutants

1971 ◽  
Vol 19 (3) ◽  
pp. 442-450 ◽  
Author(s):  
Klaus Klein ◽  
Regina Steinberg ◽  
Brigitte Fiethen ◽  
Peter Overath
Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1760-1771 ◽  
Author(s):  
Maciej W. Guzik ◽  
Tanja Narancic ◽  
Tatjana Ilic-Tomic ◽  
Sandra Vojnovic ◽  
Shane T. Kenny ◽  
...  

Diverse and elaborate pathways for nutrient utilization, as well as mechanisms to combat unfavourable nutrient conditions make Pseudomonas putida KT2440 a versatile micro-organism able to occupy a range of ecological niches. The fatty acid degradation pathway of P. putida is complex and correlated with biopolymer medium chain length polyhydroxyalkanoate (mcl-PHA) biosynthesis. Little is known about the second step of fatty acid degradation (β-oxidation) in this strain. In silico analysis of its genome sequence revealed 21 putative acyl-CoA dehydrogenases (ACADs), four of which were functionally characterized through mutagenesis studies. Four mutants with insertionally inactivated ACADs (PP_1893, PP_2039, PP_2048 and PP_2437) grew and accumulated mcl-PHA on a range of fatty acids as the sole source of carbon and energy. Their ability to grow and accumulate biopolymer was differentially negatively affected on various fatty acids, in comparison to the wild-type strain. Inactive PP_2437 exhibited a pattern of reduced growth and PHA accumulation when fatty acids with lengths of 10 to 14 carbon chains were used as substrates. Recombinant expression and biochemical characterization of the purified protein allowed functional annotation in P. putida KT2440 as an ACAD showing clear preference for dodecanoyl-CoA ester as a substrate and optimum activity at 30 °C and pH 6.5–7.


Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Yoshihiro Agari ◽  
Kazuko Agari ◽  
Keiko Sakamoto ◽  
Seiki Kuramitsu ◽  
Akeo Shinkai

In the extremely thermophilic bacterium Thermus thermophilus HB8, one of the four TetR-family transcriptional regulators, which we named T. thermophilus FadR, negatively regulated the expression of several genes, including those involved in fatty acid degradation, both in vivo and in vitro. T. thermophilus FadR repressed the expression of the target genes by binding pseudopalindromic sequences covering the predicted −10 hexamers of their promoters, and medium-to-long straight-chain (C10–18) fatty acyl-CoA molecules were effective for transcriptional derepression. An X-ray crystal structure analysis revealed that T. thermophilus FadR bound one lauroyl (C12)-CoA molecule per FadR monomer, with its acyl chain moiety in the centre of the FadR molecule, enclosed within a tunnel-like substrate-binding pocket surrounded by hydrophobic residues, and the CoA moiety interacting with basic residues on the protein surface. The growth of T. thermophilus HB8, with palmitic acid as the sole carbon source, increased the expression of FadR-regulated genes. These results indicate that in T. thermophilus HB8, medium-to-long straight-chain fatty acids can be used for metabolic energy under the control of FadR, although the major fatty acids found in this strain are iso- and anteiso-branched-chain (C15 and 17) fatty acids.


2016 ◽  
Vol 266 ◽  
pp. 219-225 ◽  
Author(s):  
Ka Him Chu ◽  
Guocheng Huang ◽  
Taicheng An ◽  
Guiying Li ◽  
Pui Ling Yip ◽  
...  

2002 ◽  
Vol 184 (13) ◽  
pp. 3759-3764 ◽  
Author(s):  
John W. Campbell ◽  
John E. Cronan

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.


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