scholarly journals Expression of a recombinant, 4’-Phosphopantetheinylated, active M. tuberculosis Fatty acid Synthase I in E. coli

2018 ◽  
Author(s):  
Szilvia Baron ◽  
Yoav Peleg ◽  
Jacob Grunwald ◽  
David Morgenstern ◽  
Nadav Elad ◽  
...  

AbstractFatty acid synthase 1 (FAS I) from Mycobacterium. tuberculosis (Mtb) is an essential protein and a promising drug target. FAS I is a multi-functional, multi-domain protein that is organized as a large (1.9 MDa) homohexameric complex. Acyl intermediates produced during fatty acid elongation are attached covalently to an acyl carrier protein (ACP) domain. This domain is activated by the transfer of a 4’-Phosphopantetheine (4’-PP, also termed P-pant) group from CoA to ACP catalyzed by a 4’-PP transferase, termed acyl carrier protein synthase (AcpS). In order to obtain an activated FAS I in E. coli, we transformed E. coli with tagged Mtb fas1 and acpS genes encoded by a separate plasmid.We induced the expression of Mtb FAS I following induction of AcpS expression. FAS I was purified by Strep-Tactin affinity chromatography. Activation of Mtb FAS I was confirmed by the identification of a bound P-pant group on serine at position 1808 by mass spectrometry. The purified FAS I displayed biochemical activity shown by spectrophotometric analysis of NADPH oxidation and by CoA production, using the Ellman reaction. The purified Mtb FAS I forms a hexameric complex shown by negative staining and cryo-EM. Purified hexameric and active Mtb FAS I is required for binding and drug inhibition studies and for structurefunction analysis of this enzyme. This relatively simple and short procedure for Mtb FAS I production should facilitate studies of this enzyme.

2000 ◽  
Vol 182 (2) ◽  
pp. 365-370 ◽  
Author(s):  
Keum-Hwa Choi ◽  
Richard J. Heath ◽  
Charles O. Rock

ABSTRACT A universal set of genes encodes the components of the dissociated, type II, fatty acid synthase system that is responsible for producing the multitude of fatty acid structures found in bacterial membranes. We examined the biochemical basis for the production of branched-chain fatty acids by gram-positive bacteria. Two genes that were predicted to encode homologs of the β-ketoacyl-acyl carrier protein synthase III of Escherichia coli (eFabH) were identified in theBacillus subtilis genome. Their protein products were expressed, purified, and biochemically characterized. Both B. subtilis FabH homologs, bFabH1 and bFabH2, carried out the initial condensation reaction of fatty acid biosynthesis with acetyl-coenzyme A (acetyl-CoA) as a primer, although they possessed lower specific activities than eFabH. bFabH1 and bFabH2 also utilized iso- and anteiso-branched-chain acyl-CoA primers as substrates. eFabH was not able to accept these CoA thioesters. Reconstitution of a complete round of fatty acid synthesis in vitro with purified E. coli proteins showed that eFabH was the only E. colienzyme incapable of using branched-chain substrates. Expression of either bFabH1 or bFabH2 in E. coli resulted in the appearance of a branched-chain 17-carbon fatty acid. Thus, the substrate specificity of FabH is an important determinant of branched-chain fatty acid production.


2001 ◽  
Vol 276 (50) ◽  
pp. 47029-47037 ◽  
Author(s):  
Merrill L. Schaeffer ◽  
Gautam Agnihotri ◽  
Craig Volker ◽  
Howard Kallender ◽  
Patrick J. Brennan ◽  
...  

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Woo Cheol Lee ◽  
Sungjae Choi ◽  
Ahjin Jang ◽  
Kkabi Son ◽  
Yangmee Kim

AbstractSome Gram-negative bacteria harbor lipids with aryl polyene (APE) moieties. Biosynthesis gene clusters (BGCs) for APE biosynthesis exhibit striking similarities with fatty acid synthase (FAS) genes. Despite their broad distribution among pathogenic and symbiotic bacteria, the detailed roles of the metabolic products of APE gene clusters are unclear. Here, we determined the crystal structures of the β-ketoacyl-acyl carrier protein (ACP) reductase ApeQ produced by an APE gene cluster from clinically isolated virulent Acinetobacter baumannii in two states (bound and unbound to NADPH). An in vitro visible absorption spectrum assay of the APE polyene moiety revealed that the β-ketoacyl-ACP reductase FabG from the A. baumannii FAS gene cluster cannot be substituted for ApeQ in APE biosynthesis. Comparison with the FabG structure exhibited distinct surface electrostatic potential profiles for ApeQ, suggesting a positively charged arginine patch as the cognate ACP-binding site. Binding modeling for the aryl group predicted that Leu185 (Phe183 in FabG) in ApeQ is responsible for 4-benzoyl moiety recognition. Isothermal titration and arginine patch mutagenesis experiments corroborated these results. These structure–function insights of a unique reductase in the APE BGC in comparison with FAS provide new directions for elucidating host–pathogen interaction mechanisms and novel antibiotics discovery.


Structure ◽  
2010 ◽  
Vol 18 (11) ◽  
pp. 1450-1462 ◽  
Author(s):  
Mohan Babu ◽  
Jack F. Greenblatt ◽  
Andrew Emili ◽  
Natalie C.J. Strynadka ◽  
Reinhart A.F. Reithmeier ◽  
...  

2000 ◽  
Vol 28 (6) ◽  
pp. 615-616 ◽  
Author(s):  
G. Honeyman ◽  
T. Fawcett

We have used a yeast two-hybrid approach to detect direct protein interactions between fatty acid synthase components. Enoyl-acyl carrier protein (ACP) reductase was found to interact with stearoyl-ACP desaturase and acyl-ACP thioesterase, but none of these proteins interacted with ACP in the yeast nucleus.


PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e57859 ◽  
Author(s):  
Uldaeliz Trujillo ◽  
Edwin Vázquez-Rosa ◽  
Delise Oyola-Robles ◽  
Loren J. Stagg ◽  
David A. Vassallo ◽  
...  

1988 ◽  
Vol 16 (3) ◽  
pp. 392-393 ◽  
Author(s):  
PHILIP S. SHELDON ◽  
RICHARD SAFFORD ◽  
ANTONI R. SLABAS ◽  
ROY G. O. KEKWICK

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