Abstract
The enoyl-(acyl-carrier protein) (ACP) reductase catalyses the last step in each cycle of fatty acid elongation in the type II fatty acid synthase systems. An extensively characterized NADH-dependent reductase, FabI, is widely distributed in bacteria and plants, whereas the enoyl-ACP reductase, FabK, is a distinctly different member of this enzyme group discovered in Streptococcus pneumoniae. We were unable to delete the fabK gene from Strep. pneumoniae, suggesting that this is the only enoyl-ACP reductase in this organism. The FabK enzyme was purified and the biochemical properties of the reductase were examined. The visible absorption spectrum of the purified protein indicated the presence of a flavin cofactor that was identified as FMN by MS, and was present in a 1:1 molar ratio with protein. FabK specifically required NADH and the protein activity was stimulated by ammonium ions. FabK also exhibited NADH oxidase activity in the absence of substrate. Strep. pneumoniae belongs to the Bacillus / Lactobacillus / Streptococcus group that includes Staphylococcus aureus and Bacillus subtilis. These two organisms also contain FabK-related genes, suggesting that they may also express a FabK-like enoyl-ACP reductase. However, the genes did not complement a fabI (Ts) mutant and the purified flavoproteins were unable to reduce enoyl-ACP in vitro and did not exhibit NAD(P)H oxidase activity, indicating they were not enoyl-ACP reductases. The restricted occurrence of the FabK enoyl-ACP reductase may be related to the role of substrate-independent NADH oxidation in oxygen-dependent anaerobic energy metabolism.
Full Text
The Full Text of this article is available as a PDF (211.8 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baker M. E. Enoyl-acyl-carrier-protein reductase and Mycobacterium tuberculosis InhA do not conserve the Tyr-Xaa-Xaa-Xaa-Lys motif in mammalian 11 beta- and 17 beta-hydroxysteroid dehydrogenases and Drosophila alcohol dehydrogenase. Biochem J. 1995 Aug 1;309(Pt 3):1029–1030. doi: 10.1042/bj3091029. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bergler H., Wallner P., Ebeling A., Leitinger B., Fuchsbichler S., Aschauer H., Kollenz G., Högenauer G., Turnowsky F. Protein EnvM is the NADH-dependent enoyl-ACP reductase (FabI) of Escherichia coli. J Biol Chem. 1994 Feb 25;269(8):5493–5496. [PubMed] [Google Scholar]
- Bhargava H. N., Leonard P. A. Triclosan: applications and safety. Am J Infect Control. 1996 Jun;24(3):209–218. doi: 10.1016/s0196-6553(96)90017-6. [DOI] [PubMed] [Google Scholar]
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
- Gibson C. M., Mallett T. C., Claiborne A., Caparon M. G. Contribution of NADH oxidase to aerobic metabolism of Streptococcus pyogenes. J Bacteriol. 2000 Jan;182(2):448–455. doi: 10.1128/jb.182.2.448-455.2000. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heath R. J., Li J., Roland G. E., Rock C. O. Inhibition of the Staphylococcus aureus NADPH-dependent enoyl-acyl carrier protein reductase by triclosan and hexachlorophene. J Biol Chem. 2000 Feb 18;275(7):4654–4659. doi: 10.1074/jbc.275.7.4654. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Rock C. O. A triclosan-resistant bacterial enzyme. Nature. 2000 Jul 13;406(6792):145–146. doi: 10.1038/35018162. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Rock C. O. Enoyl-acyl carrier protein reductase (fabI) plays a determinant role in completing cycles of fatty acid elongation in Escherichia coli. J Biol Chem. 1995 Nov 3;270(44):26538–26542. doi: 10.1074/jbc.270.44.26538. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Rock C. O. Inhibition of beta-ketoacyl-acyl carrier protein synthase III (FabH) by acyl-acyl carrier protein in Escherichia coli. J Biol Chem. 1996 May 3;271(18):10996–11000. doi: 10.1074/jbc.271.18.10996. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Rock C. O. Regulation of fatty acid elongation and initiation by acyl-acyl carrier protein in Escherichia coli. J Biol Chem. 1996 Jan 26;271(4):1833–1836. doi: 10.1074/jbc.271.4.1833. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Rock C. O. Roles of the FabA and FabZ beta-hydroxyacyl-acyl carrier protein dehydratases in Escherichia coli fatty acid biosynthesis. J Biol Chem. 1996 Nov 1;271(44):27795–27801. doi: 10.1074/jbc.271.44.27795. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Rubin J. R., Holland D. R., Zhang E., Snow M. E., Rock C. O. Mechanism of triclosan inhibition of bacterial fatty acid synthesis. J Biol Chem. 1999 Apr 16;274(16):11110–11114. doi: 10.1074/jbc.274.16.11110. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Su N., Murphy C. K., Rock C. O. The enoyl-[acyl-carrier-protein] reductases FabI and FabL from Bacillus subtilis. J Biol Chem. 2000 Dec 22;275(51):40128–40133. doi: 10.1074/jbc.M005611200. [DOI] [PubMed] [Google Scholar]
- Heath R. J., Yu Y. T., Shapiro M. A., Olson E., Rock C. O. Broad spectrum antimicrobial biocides target the FabI component of fatty acid synthesis. J Biol Chem. 1998 Nov 13;273(46):30316–30320. doi: 10.1074/jbc.273.46.30316. [DOI] [PubMed] [Google Scholar]
- Håvarstein L. S., Coomaraswamy G., Morrison D. A. An unmodified heptadecapeptide pheromone induces competence for genetic transformation in Streptococcus pneumoniae. Proc Natl Acad Sci U S A. 1995 Nov 21;92(24):11140–11144. doi: 10.1073/pnas.92.24.11140. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McMurry L. M., Oethinger M., Levy S. B. Triclosan targets lipid synthesis. Nature. 1998 Aug 6;394(6693):531–532. doi: 10.1038/28970. [DOI] [PubMed] [Google Scholar]
- Parikh S., Moynihan D. P., Xiao G., Tonge P. J. Roles of tyrosine 158 and lysine 165 in the catalytic mechanism of InhA, the enoyl-ACP reductase from Mycobacterium tuberculosis. Biochemistry. 1999 Oct 12;38(41):13623–13634. doi: 10.1021/bi990529c. [DOI] [PubMed] [Google Scholar]
- Rock C. O., Cronan J. E. Escherichia coli as a model for the regulation of dissociable (type II) fatty acid biosynthesis. Biochim Biophys Acta. 1996 Jul 12;1302(1):1–16. doi: 10.1016/0005-2760(96)00056-2. [DOI] [PubMed] [Google Scholar]
- Rock C. O., Garwin J. L. Preparative enzymatic synthesis and hydrophobic chromatography of acyl-acyl carrier protein. J Biol Chem. 1979 Aug 10;254(15):7123–7128. [PubMed] [Google Scholar]
- Ross R. P., Claiborne A. Molecular cloning and analysis of the gene encoding the NADH oxidase from Streptococcus faecalis 10C1. Comparison with NADH peroxidase and the flavoprotein disulfide reductases. J Mol Biol. 1992 Oct 5;227(3):658–671. doi: 10.1016/0022-2836(92)90215-6. [DOI] [PubMed] [Google Scholar]
- Roujeinikova A., Levy C. W., Rowsell S., Sedelnikova S., Baker P. J., Minshull C. A., Mistry A., Colls J. G., Camble R., Stuitje A. R. Crystallographic analysis of triclosan bound to enoyl reductase. J Mol Biol. 1999 Nov 26;294(2):527–535. doi: 10.1006/jmbi.1999.3240. [DOI] [PubMed] [Google Scholar]
- Roujeinikova A., Sedelnikova S., de Boer G. J., Stuitje A. R., Slabas A. R., Rafferty J. B., Rice D. W. Inhibitor binding studies on enoyl reductase reveal conformational changes related to substrate recognition. J Biol Chem. 1999 Oct 22;274(43):30811–30817. doi: 10.1074/jbc.274.43.30811. [DOI] [PubMed] [Google Scholar]
- Suller M. T., Russell A. D. Triclosan and antibiotic resistance in Staphylococcus aureus. J Antimicrob Chemother. 2000 Jul;46(1):11–18. doi: 10.1093/jac/46.1.11. [DOI] [PubMed] [Google Scholar]
- Tchorzewski M., Kurihara T., Esaki N., Soda K. Unique primary structure of 2-nitropropane dioxygenase from Hansenula mrakii. Eur J Biochem. 1994 Dec 15;226(3):841–846. doi: 10.1111/j.1432-1033.1994.00841.x. [DOI] [PubMed] [Google Scholar]
- Throup J. P., Koretke K. K., Bryant A. P., Ingraham K. A., Chalker A. F., Ge Y., Marra A., Wallis N. G., Brown J. R., Holmes D. J. A genomic analysis of two-component signal transduction in Streptococcus pneumoniae. Mol Microbiol. 2000 Feb;35(3):566–576. doi: 10.1046/j.1365-2958.2000.01725.x. [DOI] [PubMed] [Google Scholar]
- Ward W. H., Holdgate G. A., Rowsell S., McLean E. G., Pauptit R. A., Clayton E., Nichols W. W., Colls J. G., Minshull C. A., Jude D. A. Kinetic and structural characteristics of the inhibition of enoyl (acyl carrier protein) reductase by triclosan. Biochemistry. 1999 Sep 21;38(38):12514–12525. doi: 10.1021/bi9907779. [DOI] [PubMed] [Google Scholar]
