Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxygenase with a bacterial type-I fatty acid synthase in E. coli

Mycolic acids are vital components of theMycobacterium tuberculosiscell wall, and enzymes involved in their formation represent attractive targets for the discovery of novel anti-tuberculosis agents. Biosynthesis of the fatty acyl chains of mycolic acids involves two fatty acid synthetic systems, the multifunctional polypeptide fatty acid synthase I (FASI), which performsde novofatty acid synthesis, and the dissociated FASII system, which consists of monofunctional enzymes, and acyl carrier protein (ACP) and elongates FASI products to long chain mycolic acid precursors. In this study, we present the initial characterization of purified KasA and KasB, two β-ketoacyl-ACP synthase (KAS) enzymes of theM. tuberculosisFASII system. KasA and KasB were expressed inE. coliand purified by affinity chromatography. Both enzymes showed activity typical of bacterial KASs, condensing an acyl-ACP with malonyl-ACP. Consistent with the proposed role of FASII in mycolic acid synthesis, analysis of various acyl-ACP substrates indicated KasA and KasB had higher specificity for long chain acyl-ACPs containing at least 16 carbons. Activity of KasA and KasB increased with use ofM. tuberculosisAcpM, suggesting that structural differences between AcpM andE. coliACP may affect their recognition by the enzymes. Both enzymes were sensitive to KAS inhibitors cerulenin and thiolactomycin. These results represent important steps in characterizing KasA and KasB as targets for antimycobacterial drug discovery.

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Malonyl-CoA and the regulation of fatty acid oxidation in soleus muscle

Biochemical Journal ◽

10.1042/bj3340233 ◽

1998 ◽

Vol 334 (1) ◽

pp. 233-241 ◽

Cited By ~ 99

Author(s):

Nasreen ALAM ◽

E. David SAGGERSON

Keyword(s):

Skeletal Muscle ◽

Fatty Acid ◽

Soleus Muscle ◽

Fatty Acid Synthase ◽

Fatty Acyl ◽

Acid Oxidation ◽

Type I ◽

Tissue Content ◽

Malonyl Coa ◽

Long Chain

1. Rat soleus strips were incubated with 5 mM glucose, after which tissue metabolites were measured. Alternatively, muscle strips were incubated with 5 mM glucose and 0.2 mM palmitate, and the formation of 14CO2 from exogenous palmitate or from fatty acids released from prelabelled glycerolipids was measured. 2. Etomoxir, which inhibits the mitochondrial overt form of carnitine palmitoyltransferase (CPT1), increased the tissue content of long-chain fatty acyl-CoA esters and decreased the ratio of fatty acylcarnitine to fatty acyl-CoA, suggesting that such changes could be a diagnostic for the inhibition of CPT1. 3. Over a range of incubation conditions there was a positive correlation between the tissue contents of malonyl-CoA and long-chain fatty acyl-CoA esters. Under conditions in which these two metabolites increased in content (i.e. with insulin or with 3 mM dichloroacetate) there was a corresponding decrease in the ratio of fatty acylcarnitine to fatty acyl-CoA and a decrease in β-oxidation. Isoprenaline or palmitate (0.5 mM) opposed the effect of insulin, decreasing the contents of malonyl-CoA and long-chain fatty acyl-CoA, increasing the ratio of fatty acylcarnitine to fatty acyl-CoA and increasing β-oxidation. These findings are consistent with the notion that all of these agents can cause the acute regulation of CPT1 in Type I skeletal muscle. 4. The addition of 5-amino-4-imidazolecarboxamide ribonucleoside (AICAriboside) to cause activation of the AMP-activated protein kinase decreased the tissue content of malonyl-CoA. AICAriboside also had an antilipolytic effect in the muscle strips. 5. Measurements were made of the activities of ATP-citrate lyase, acetyl-CoA carboxylase, fatty acid synthase and malonyl-CoA decarboxylase in soleus muscle and in representative Type IIa and Type IIb muscles. A cytosolic activity of malonyl-CoA decarboxylase would seem to offer a feasible route for the disposal of malonyl-CoA in skeletal muscle.

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Mycobacterial fatty acid catabolism is repressed by FdmR to sustain lipogenesis and virulence

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2019305118 ◽

2021 ◽

Vol 118 (16) ◽

pp. e2019305118

Author(s):

Wenyue Dong ◽

Xiaoqun Nie ◽

Hong Zhu ◽

Qingyun Liu ◽

Kunxiong Shi ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Carbon Source ◽

Fatty Acid Synthase ◽

Cell Envelope ◽

Flux Analysis ◽

Type I ◽

Chain Acyl ◽

Fatty Acid Catabolism ◽

Long Chain

Host-derived fatty acids are an important carbon source for pathogenic mycobacteria during infection. How mycobacterial cells regulate the catabolism of fatty acids to serve the pathogenicity, however, remains unknown. Here, we identified a TetR-family transcriptional factor, FdmR, as the key regulator of fatty acid catabolism in the pathogen Mycobacterium marinum by combining use of transcriptomics, chromatin immunoprecipitation followed by sequencing, dynamic 13C-based flux analysis, metabolomics, and lipidomics. An M. marinum mutant deficient in FdmR was severely attenuated in zebrafish larvae and adult zebrafish. The mutant showed defective growth but high substrate consumption on fatty acids. FdmR was identified as a long-chain acyl-coenzyme A (acyl-CoA)–responsive repressor of genes involved in fatty acid degradation and modification. We demonstrated that FdmR functions as a valve to direct the flux of exogenously derived fatty acids away from β-oxidation toward lipid biosynthesis, thereby avoiding the overactive catabolism and accumulation of biologically toxic intermediates. Moreover, we found that FdmR suppresses degradation of long-chain acyl-CoAs endogenously synthesized through the type I fatty acid synthase. By modulating the supply of long-chain acyl-CoAs for lipogenesis, FdmR controls the abundance and chain length of virulence-associated lipids and mycolates and plays an important role in the impermeability of the cell envelope. These results reveal that despite the fact that host-derived fatty acids are used as an important carbon source, overactive catabolism of fatty acids is detrimental to mycobacterial cell growth and pathogenicity. This study thus presents FdmR as a potentially attractive target for chemotherapy.

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3-Aryl-4-hydroxyquinolin-2(1H)-one derivatives as type I fatty acid synthase inhibitors

Bioorganic & Medicinal Chemistry Letters ◽

10.1016/j.bmcl.2006.06.014 ◽

2006 ◽

Vol 16 (17) ◽

pp. 4620-4623 ◽

Cited By ~ 37

Author(s):

Alexey Rivkin ◽

Yoona R. Kim ◽

Mark T. Goulet ◽

Nathan Bays ◽

Armetta D. Hill ◽

...

Keyword(s):

Fatty Acid ◽

Fatty Acid Synthase ◽

Type I

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Biocatalyst Engineering by Assembly of Fatty Acid Transport and Oxidation Activities for In Vivo Application of Cytochrome P-450BM-3 Monooxygenase

Applied and Environmental Microbiology ◽

10.1128/aem.64.10.3784-3790.1998 ◽

1998 ◽

Vol 64 (10) ◽

pp. 3784-3790 ◽

Cited By ~ 42

Author(s):

Silke Schneider ◽

Marcel G. Wubbolts ◽

Dominique Sanglard ◽

Bernard Witholt

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Coenzyme A ◽

Fatty Acid Uptake ◽

Acid Uptake ◽

Uptake System ◽

Whole Cells ◽

E Coli ◽

Cytochrome P 450 ◽

Long Chain

ABSTRACT The application of whole cells containing cytochrome P-450BM-3 monooxygenase [EC 1.14.14.1 ] for the bioconversion of long-chain saturated fatty acids to ω-1, ω-2, and ω-3 hydroxy fatty acids was investigated. We utilized pentadecanoic acid and studied its conversion to a mixture of 12-, 13-, and 14-hydroxypentadecanoic acids by this monooxygenase. For this purpose,Escherichia coli recombinants containing plasmid pCYP102 producing the fatty acid monooxygenase cytochrome P-450BM-3were used. To overcome inefficient uptake of pentadecanoic acid by intact E. coli cells, we made use of a cloned fatty acid uptake system from Pseudomonas oleovorans which, in contrast to the common FadL fatty acid uptake system of E. coli, does not require coupling by FadD (acyl-coenzyme A synthetase) of the imported fatty acid to coenzyme A. This system fromP. oleovorans is encoded by a gene carried by plasmid pGEc47, which has been shown to effect facilitated uptake of oleic acid in E. coli W3110 (M. Nieboer, Ph.D. thesis, University of Groningen, Groningen, The Netherlands, 1996). By using a double recombinant of E. coli K27, which is a fadDmutant and therefore unable to consume substrates or products via the β-oxidation cycle, a twofold increase in productivity was achieved. Applying cytochrome P-450BM-3 monooxygenase as a biocatalyst in whole cells does not require the exogenous addition of the costly cofactor NADPH. In combination with the coenzyme A-independent fatty acid uptake system from P. oleovorans, cytochrome P-450BM-3 recombinants appear to be useful alternatives to the enzymatic approach for the bioconversion of long-chain fatty acids to subterminal hydroxylated fatty acids.

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