Structure and function of animal fatty acid synthase

Abstract

Fatty acid synthase (FAS; EC 2.3.1.85) of animal tissues is a complex multifunctional enzyme consisting of two identical monomers. The FAS monomer (∼270 kDa) contains six catalytic activities and from the N-terminus the order is β-ketoacyl synthase (KS), acetyl/malonyl transacylase (AT/MT), β-hydroxyacyl dehydratase (DH), enoyl reductase (ER), β-ketoacyl reductase (KR), acyl carrier protein (ACP), and thioesterase (TE). Although the FAS monomer contains all the activities needed for palmitate synthesis, only the dimer form of the synthase is functional. Both the biochemical analyses and the small-angle neutron-scattering analysis determined that in the dimer form of the enzyme the monomers are arranged in a head-to-tail manner generating two centers for palmitate synthesis. Further, these analyses also suggested that the component activities of the monomer are organized in three domains. Domain I contains KS, AT/MT, and DH, domain II contains ER, KR, and ACP, and domain III contains TE. Approximately one fourth of the monomer protein located between domains I and II contains no catalytic activities and is called the interdomain/core region. This region plays an important role in the dimer formation. Electron cryomicrographic analyses of FAS revealed a quaternary structure at approximately 19 Å resolution, containing two monomers (180×130×75 Å) that are separated by about 19 Å, and arranged in an antiparallel fashion, which is consistent with biochemical and neutron-scattering data. The monomers are connected at the middle by a hinge generating two clefts that may be the two active centers of fatty acid synthesis. Normal mode analysis predicted that the intersubunit hinge region and the intrasubunit hinge located between domains II and III are highly flexible. Analysis of FAS particle images by using a simultaneous multiple model single particle refinement method confirmed that FAS structure exists in various conformational states. Attempts to get higher resolution of the structure are under way.

This is a preview of subscription content, log in to check access.

Abbreviations

ACP:

acyl carrier protein

AT/MT:

acetyl/malonyl transacylase

DH:

dehydratase

DI to DIII:

domains I to III

ER:

enoyl reductase

FAS:

fatty acid synthase

KR:

ketoacyl reductase

KS:

ketoacyl synthase

TE:

thioesterase

References

  1. 1.

    Wakil, S.J., Stoops, J.K., and Joshi, A.C. (1983) Fatty Acid Synthesis and Its Regulation, Annu. Rev. Biochem. 52, 537–579.

    PubMed  Article  CAS  Google Scholar 

  2. 2.

    Wakil, S.J. (1989) The Fatty Acid Synthase: A Proficient Multifunctional Enzyme, Biochemistry 28, 4523–4530.

    PubMed  Article  CAS  Google Scholar 

  3. 3.

    Smith, S. (1994) The Animal Fatty Acid Synthase: One Gene, One Polypeptide, Seven Enzymes, FASEB J. 8, 1248–1259.

    PubMed  CAS  Google Scholar 

  4. 4.

    Smith, S., Witkowski, A., and Joshi, A.K. (2003) Structural and Functional Organization of Animal Fatty Acid Synthase, Prog. Lipid Res. 42, 289–317.

    PubMed  Article  CAS  Google Scholar 

  5. 5.

    Jayakumar, A., Tai, M.-H., Huang, W.-Y., Al-Feel, W., Hsu, M., Abu-Elheiga, L., Chirala, S.S., and Wakil, S.J. (1995) Human Fatty Acid Synthase: Properties and Molecular Cloning, Proc. Natl. Acad. Sci. USA 92, 8695–8699.

    PubMed  Article  CAS  Google Scholar 

  6. 6.

    Hannun, Y.A., and Obeid, L.M. (2002) The Ceramide-Centric Universe of Lipid-Mediated Cell Regulation: Stress Encounters of the Lipid Kind, J. Biol. Chem. 277, 25847–25850.

    PubMed  Article  CAS  Google Scholar 

  7. 7.

    Kuhajda, F.P., Jenner, K., Wood, F.D., Hennigar, R.A., Jacobs, L.B., Dick, J.D., and Pasternack, G.R. (1994) Fatty Acid Synthesis: A Potential Selective Target for Antineoplastic Therapy, Proc. Natl. Acad. Sci. USA 91, 6379–6383.

    PubMed  Article  CAS  Google Scholar 

  8. 8.

    Pizer, E.S., Thupari, J., Han, W.F., Pinn, M.L., Cherst, F.J., Frehywot, G.L., Townsend, C.A., and Kuhajda, F.P. (2000) Malonyl-CoA Is a Potential Mediator of Cytotoxicity Induced by Fatty Acid Synthase Inhibition in Human Breast Cancer Cells and Xenografts, Cancer Res. 60, 213–238.

    PubMed  CAS  Google Scholar 

  9. 9.

    Menendez, J.A., Vellon, L., Mehmi, I., Oza, B.P., Ropero, S., Colomer, R., and Lupu, R. (2004) Inhibition of Fatty Acid Synthase (FAS) Suppresses HER2/neu (erbB-2) Oncogene Overexpression in Cancer Cells, Proc. Natl. Acad. Sci. USA 101, 10715–10720.

    PubMed  Article  CAS  Google Scholar 

  10. 10.

    Loftus, T.M., Jaworsky, D.E., Frehywot, G.L., Towsand, C.A., Ronnett, G.V., Lane, M.D., and Kuhajda, F.P. (2000) Reduced Food Intake and Body Weight in Mice Treated with Fatty Acid Synthase Inhibitors, Science 288, 2379–2381.

    PubMed  Article  CAS  Google Scholar 

  11. 11.

    Chirala, S.S., Chang, H., Matzuk, M., Abu-Elheiga, L., Mao, J., Mahon, K., Finegold, M., and Wakil, S.J. (2003) Fatty Acid Synthesis Is Essential in Embryonic Development: Fatty Acid Synthase Null Mutants and Most of the Heterozygotes Die In Utero, Proc. Natl. Acad. Sci. USA 100, 6358–6363.

    PubMed  Article  CAS  Google Scholar 

  12. 12.

    Wakil, S.J. (1970) Fatty Acid Metabolism, in Lipid Metabolism (Wakil, S.J., ed.), pp. 1–48, Academic Press, New York.

    Google Scholar 

  13. 13.

    Wakil, S.J. (1958) Requirement of Bicarbonate in Fatty Acid Synthesis, J. Am. Chem. Soc. 80, 2908.

    Article  Google Scholar 

  14. 14.

    Wakil, S.J., Pugh, E.L., and Sauer, F. (1964) The Mechanism of Fatty Acid Synthesis, Proc. Natl. Acad. Sci. USA 52, 106–114.

    PubMed  Article  CAS  Google Scholar 

  15. 15.

    Stoops, J.K., Arslanian, A.W., Oh, Y.H., Aune, K.C., Vanaman, T.C., and Wakil, S.J. (1975) Presence of Two Polypeptide Chains Comprising Fatty Acid Synthetase, Proc. Natl. Acad. Sci. USA 75, 1940–1944.

    Article  Google Scholar 

  16. 16.

    Stoops, J.K., Arslanian, A.W., Chalmers, J.H., Joshi, V.C., and Wakil, S.J. (1977) Fatty Acid Synthase Complexes, in Bioorganic Chemistry (Van Tamelien, E.E., ed.), Vol. 1, pp. 339–370, Academic Press, New York.

    Google Scholar 

  17. 17.

    Tsukamoto, Y., and Wakil, S.J. (1988) Isolation and Mapping of the Beta-Hydroxyacyl Dehydratase Activity of Chicken Liver Fatty Acid Synthase, J. Biol. Chem. 263, 16225–16229.

    PubMed  CAS  Google Scholar 

  18. 18.

    Chirala, S.S., Kasturi, R., Pazirandeh, M., Stolow, D.T., Huang, W.-Y., and Wakil, S.J. (1989) A Novel cDNA Extension Procedure: Isolation of Chicken Fatty Acid Synthase cDNA Clones, J. Biol. Chem. 264, 3750–3757.

    PubMed  CAS  Google Scholar 

  19. 19.

    Holzer, K.R., Liu, W., and Hammes, G.G. (1989) Molecular Cloning and Sequencing of Chicken Liver Fatty Acid Synthase cDNA, Proc. Natl. Acad. Sci. USA 86, 4387–4391.

    PubMed  Article  CAS  Google Scholar 

  20. 20.

    Haung, W.-Y., Chirala, S.S., and Wakil, S.J. (1994) Amino-Terminal Blocking Group and Sequence of the Animal Fatty Acid Synthase, Arch. Biochem. Biophys. 314, 45–49.

    Article  Google Scholar 

  21. 21.

    Amy, C.M., Witkowski, A., Naggert, J., Williams, B., Randhawa, Z., and Smith, S. (1989) Molecular Cloning and Sequencing of cDNAs Encoding the Entire Rat Fatty Acid Synthase, Proc. Natl. Acad. Sci. USA 86, 3114–3118.

    PubMed  Article  CAS  Google Scholar 

  22. 22.

    Beck, K.-I., Schreglmann, R., Stathopulos, I., Klein, H., Hoch, J., and Schweizer, M. (1992) The Fatty Acid Synthase (FAS) Gene and Its Promoter in Rattus Norvegicus, DNA Seq. 2, 359–386.

    PubMed  CAS  Google Scholar 

  23. 23.

    Paulauskis, J.D., and Sul, H.S. (1989) Structure of Mouse Fatty Acid Synthase mRNA: Identification of the Two NADPH Binding Sites, Biochem. Biophys. Res. Commun. 158, 690–695.

    PubMed  Article  CAS  Google Scholar 

  24. 24.

    Chirala, S.S., Huang, W.-Y., Jayakumar, A., Sakai, K., and Wakil, S.J. (1997) Animal Fatty Acid Synthase: Functional Mapping and Cloning and Expression of the Domain I Constituent Activities, Proc. Natl. Acad. Sci. USA 94, 5588–5593.

    PubMed  Article  CAS  Google Scholar 

  25. 25.

    Stoops, J.K., and Wakil, S.J. (1981) Animal Fatty Acid Synthase: A Novel Arrangement of the β-Ketoacyl Synthase Site Comprising Domains of the Subunits, J. Biol. Chem. 256, 5128–5133.

    PubMed  CAS  Google Scholar 

  26. 26.

    Stoops, J.K., Wakil, S.J., Uberbacher, E.C., and Bunick, G.J. (1987) Small-Angle Neutron-Scattering and Electron Microscopic Studies of the Chicken Liver Fatty Acid Synthase, J. Biol. Chem. 262, 10246–10251.

    PubMed  CAS  Google Scholar 

  27. 27.

    Singh, N., Wakil, S.J., and Stoops, J.K. (1984) On the Question of Half or Full-Site Reactivity of Animal Fatty Acid Synthetase, J. Biol. Chem. 259, 3605–3611.

    PubMed  CAS  Google Scholar 

  28. 28.

    Rangan, V.S., and Smith, S. (1996) Expression in Escherichia Coli and Refolding of the Malonyl-Acetyltransferase Domain of the Multifunctional Animal Fatty Acid Synthase, J. Biol. Chem. 271, 31749–31755.

    PubMed  Article  CAS  Google Scholar 

  29. 29.

    Rangan, V.S., and Smith, S. (1997) Alteration of the Substrate Specificity of the Malonyl-CoA/Acetyl-CoA:Acyl Carrier Protein S-Acyltransferase Domain of the Multi Functional Fatty Acid Synthase by Mutation of a Single Arginine Residue, J. Biol. Chem. 272, 11975–11978.

    PubMed  Article  CAS  Google Scholar 

  30. 30.

    Joshi, A.K., Witkowski, A., and Smith, S. (1997) Mapping of Functional Interactions Between Domains of the Animal Fatty Acid Synthase by Mutant Complementation In Vitro, Biochemistry 36, 2316–2322.

    PubMed  Article  CAS  Google Scholar 

  31. 31.

    Witkowski, A., Joshi, A.K., Lindqvist, Y., and Smith, S. (1999) Conversion of β-Ketoacyl Synthase to a Malonyl Decarboxylase by Replacement of the Active-Site Cysteine with Glutamine, Biochemistry 38, 11643–11650.

    PubMed  Article  CAS  Google Scholar 

  32. 32.

    Witkowski, A., Joshi, A.K., and Smith, S. (1996) Mechanism of the_-Ketoacyl Synthase Reaction Catalyzed by the Animal Fatty Acid Synthase, Biochemistry 41, 10887–10887.

    Google Scholar 

  33. 33.

    Rangan, V.S., Joshi, A.K., and Smith, S. (2001). Mapping the Functional Topology of the Animal Fatty Acid Synthase by Mutant Complementation In Vitro, Biochemistry 40, 10792–10799.

    PubMed  Article  CAS  Google Scholar 

  34. 34.

    Joshi, A.K., and Smith, S. (1993). Construction, Expression, and Characterization of a Mutated Animal Fatty Acid Synthase Deficient in the Dehydrase Function, J. Biol. Chem. 268, 22508–22513.

    PubMed  CAS  Google Scholar 

  35. 35.

    Pazirandeh, M., Chirala, S.S., Huang, W.-Y., and Wakil, S.J. (1989) Characterization of Recombinant Thioesterase and Acyl Carrier Protein Domains of Chicken Fatty Acid Synthase Expressed in Escherichia Coli, J. Biol. Chem. 264, 18195–18201.

    PubMed  CAS  Google Scholar 

  36. 36.

    Pazirandeh, M., Chirala, S.S., and Wakil, S.J. (1991) Site-Directed Mutagenesis Studies on the Recombinant Thioesterase Domain of Chicken Fatty Acid Synthase Expressed in Escherichia Coli, J. Biol. Chem. 266, 20946–20952.

    PubMed  CAS  Google Scholar 

  37. 37.

    Tai, M.H., Chirala, S.S., and Wakil, S.J. (1993) Roles of Ser101, Asp236, and His237 in Catalysis of Thioesterase II and of the C-terminal Region of the Enzyme in Its Interaction with Fatty Acid Synthase, Proc. Natl. Acad. Sci. USA 90, 1852–1856.

    PubMed  Article  CAS  Google Scholar 

  38. 38.

    Chakravarty, B., Gu, Z., Chirala, S.S., Wakil, S.J., Quiocho, F.A. (2004) Human Fatty Acid Synthase: Structure and Substrate Selectivity of the Thioesterase Domain, Proc. Natl. Acad. Sci. USA 101, 15567–15572.

    PubMed  Article  CAS  Google Scholar 

  39. 39.

    Jayakumar, A., Chirala, S.S., and Wakil, S.J. (1997) Human Fatty Acid Synthase: Assembling Recombinant Halves of the Fatty Acid Synthase Subunit Protein Reconstitutes Enzyme Activity, Proc. Natl. Acad. Sci. USA 94, 12326–12330.

    PubMed  Article  CAS  Google Scholar 

  40. 40.

    Chirala, S.S., Jayakumar, A., Gu, Z.-W., and Wakil, S.J. (2001) Human Fatty Acid Synthase: Role of Interdomain in the Formation of Catalytically Active Synthase Dimer, Proc. Natl. Acad. Sci. USA 98, 3104–3108.

    PubMed  Article  CAS  Google Scholar 

  41. 41.

    Joshi, A.K., Witkowski, A., and Smith, S. (1998) The Malonyl/Acetyltransferase and β-Ketoacyl Synthase Domains of the Animal Fatty Acid Synthase Can Cooperate with the Acyl Carrier Protein Domain of Either Subunit, Biochemistry 37, 2515–2523.

    PubMed  Article  CAS  Google Scholar 

  42. 42.

    Witkowski, A., Joshi, A.K., Rangan, V.S., Falick, A.M., Witkowska, H.E., and Smith, S. (1999). Dibromopropanone Cross-Linking of the Phosphopantetheine and Active-Site Cysteine Thiols of the Animal Fatty Acid Synthase Can Occur Both Inter-and Intrasubunit. Reevaluation of the Side-by-Side, Antiparallel Subunit Model, J. Biol. Chem. 274, 11557–11563.

    PubMed  Article  CAS  Google Scholar 

  43. 44.

    Joshi, A.K., Rangan, V.S., Witkowski, A., and Smith, S. (2003). Engineering of an Active Animal Fatty Acid Synthase Dimer with Only One Competent Subunit, Chem. Biol. 10, 169–173.

    PubMed  Article  CAS  Google Scholar 

  44. 45.

    Brink, J., Ludtke, S.J., Yang, C.-Y., Gu, Z.-W., Wakil, S.J., and Chiu, W. (2002) Quaternary Structure of Human Fatty Acid Synthase by Electron Cryomicroscopy, Proc. Natl. Acad. Sci. USA 99, 13–143.

    Article  Google Scholar 

  45. 46.

    Ludtke, S.J., Baldwin, P.R., and Chiu, W. (1999). EMAN: Semiautomated Software for High-Resolution Single-Particle Reconstructions, J. Struct. Biol. 128, 82–97.

    PubMed  Article  CAS  Google Scholar 

  46. 47.

    Ming, D., Kong, Y., Wakil, S.J., Brink, J., and Ma, J. (2002) Domain Movements in Human Fatty Acid Synthase by Quantized Elastic Deformational Model, Proc. Natl. Acad. Sci. USA 99, 7895–7899.

    PubMed  Article  CAS  Google Scholar 

  47. 48.

    Ming, D., Kong, Y., Lambert, M.A., Huang, Z., and Ma, J. (2002). How To Describe Protein Motion Without Amino Acid Sequence and Atomic Coordinates, Proc. Natl. Acad. Sci. USA 99, 8620–8625.

    PubMed  Article  CAS  Google Scholar 

  48. 49.

    Brink, J., Ludtke, S.J., Kong, Y., Wakil, S.J., Ma, J., and Chiu, W. (2004) Experimental Verification of Conformational Variation of Human Fatty Acid Synthase as Predicted by Normal Mode Analysis, Structure (Cambr.) 12, 185–191.

    CAS  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Salih J. Wakil.

About this article

Cite this article

Chirala, S.S., Wakil, S.J. Structure and function of animal fatty acid synthase. Lipids 39, 1045–1053 (2004). https://doi.org/10.1007/s11745-004-1329-9

Download citation

Keywords

  • Palmitate
  • Fatty Acid Synthesis
  • Acyl Carrier Protein
  • Normal Mode Analysis
  • Enoyl Reductase