Skip to main content
SpringerLink
Log in

Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed

  • Published:
Plant Molecular Biology Aims and scope Submit manuscript

Abstract

A cDNA for a structurally variant acyl-acyl carrier protein (ACP) desaturase was isolated from milkweed (Asclepias syriaca) seed, a tissue enriched in palmitoleic (16:1Δ9)* and cis-vaccenic (18:1Δ11) acids. Extracts of Escherichia coli that express the milkweed cDNA catalyzed Δ9 desaturation of acyl-ACP substrates, and the recombinant enzyme exhibited seven- to ten-fold greater specificity for palmitoyl (16:0)-ACP and 30-fold greater specificity for myristoyl (14:0)-ACP than did known Δ9-stearoyl (18:0)-ACP desaturases. Like other variant acyl-ACP desaturases reported to date, the milkweed enzyme contains fewer amino acids near its N-terminus compared to previously characterized Δ9-18:0-ACP desaturases. Based on the activity of an N-terminal deletion mutant of aΔ9 -18:0-ACP desaturase, this structural feature likely does not account for differences in substrate specificities.

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

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

References

  1. Cahoon EB, Becker CK, Shanklin J, Ohlrogge JB: cDNAs for isoforms of the △9-stearoyl-acyl carrier protein desaturase from Thunbergia alata endosperm. Plant Physiol 106: 807–808 (1994).

    Google Scholar 

  2. Cahoon EB, Crammer AM, Shanklin J, Ohlrogge JB: △6 Hexadecenoic acid is synthesized by the activity of a soluble △6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm. J Biol Chem 269: 27519–27526 (1994).

    Google Scholar 

  3. Cahoon EB, Ohlrogge JB: Metabolic evidence for the involvement of a △4-palmitoyl-acyl carrier protein desaturase in the synthesis of petroselinic acid in coriander endosperm and transgenic tobacco cells. Plant Physiol 104: 827–8389 (1994).

    Google Scholar 

  4. Cahoon EB, Shanklin J, Ohlrogge JB: Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco. Proc Natl Acad Sci USA 89: 11184–11188 (1992).

    Google Scholar 

  5. Chisholm MJ, Hopkins CY: 11-Octadecenoic acid and other fatty acids of Asclepias syriaca seed oil. Can J Chem 38: 805–812 (1960).

    Google Scholar 

  6. Chisholm MJ, Hopkins CY: Fatty acids of Doxantha seed oil. J Am Oil Chem Soc 42: 49–50 (1965).

    Google Scholar 

  7. Fox BG, Shanklin J, Somerville C, Münck E: Stearoyl-acyl carrier protein △9 desaturase from Ricinus communis is a diironoxo protein. Proc Natl Acad Sci USA 90: 2486–2490 (1993).

    Google Scholar 

  8. Gavel Y, von Heijne, G: A conserved cleavage-site motif in chloroplast transit peptides. FEBS Lett 261: 455–458 (1990).

    Google Scholar 

  9. Gibson KJ: Palmitoleate formation by soybean stearoyl-acyl carrier protein desaturase. Biochem Biophys Acta 1169: 231–235 (1993).

    Google Scholar 

  10. Jaworski JG, Stumpf PK: Fat metabolism in plants. properties of a soluble stearoylacyl carrier protein desaturase from maturing Carthamus tinctorius. Arch Biochem Biophys 162: 158–165 (1974).

    Google Scholar 

  11. Hopkins CY, Chisholm MJ: Development of oil in the seed of Asclepias syriaca L. Can J Biochem Physiol 39: 829–835 (1961).

    Google Scholar 

  12. Kleiman R, Payne-Wahl KL: Fatty acid composition of seed oils of the Meliaceae, including one genus rich in cis-vaccenic acid. J Am Oil Chem Soc 61: 1836–1838 (1984).

    Google Scholar 

  13. Lindqvist Y, Huang W, Schneider G, Shanklin J: Crystal structure of △9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins. EMBO J 15: 4081–4092 (1996).

    Google Scholar 

  14. Magnuson K, Jackowski S, Rock CO, Cronan Jr. JE: Regulation of fatty acid biosynthesis in Escherichia coli. Microbiol Rev 57: 522–542 (1993).

    Google Scholar 

  15. McKeon TA, Stumpf PK: Purification and characterization of the stearoyl-acyl carrier protein desaturase and the acyl-acyl carrier protein thioesterase from maturing seeds of safflower. J Biol Chem 257: 12141–12147 (1982).

    Google Scholar 

  16. Morris LJ, Wharry DM, Hammond EW: Chromatographic behaviour of isomeric long-chain aliphatic compounds. II. Argentation thin-layer chromatography of isomeric octadecenoates. J Chromatog 31: 69–76 (1967).

    Google Scholar 

  17. Nagai J, Bloch K: Enzymatic desaturation of stearyl acyl carrier protein. J Biol Chem 243: 4626–4633 (1968).

    Google Scholar 

  18. Ohlrogge J, Browse J: Lipid biosynthesis. Plant Cell 7: 957–970 (1995).

    Google Scholar 

  19. Rock CO, Garwin JL: Preparative enzymatic synthesis and hydrophobic chromatography of acyl-acyl carrier protein. J Biol Chem 254: 7123–7128 (1979).

    Google Scholar 

  20. Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (1989).

    Google Scholar 

  21. Schultz DJ, Cahoon DB, Shanklin J, Craig R, Cox-Foster DL, Mumma RO, Medford JI: Expression of a△9 14:0-acyl carrier protein fatty acid desaturase gene is necessary for the production of ω5 anacardic acids found in pest-resistant geranium (Pelargonium xhortorum). Proc Natl Acad Sci USA 93: 8771–8775 (1996).

    Google Scholar 

  22. Shanklin J, Somerville C: Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs. Proc Natl Acad Sci USA 88: 2510–2514 (1991).

    Google Scholar 

  23. Shibahara A, Yamamoto K, Nakayama T, Kajimoto G: cis-Vaccenic acid in pulp lipids of commonly available fruits. J Am Oil Chem Soc 64: 397–401 (1987).

    Google Scholar 

  24. Shibahara A, Yamamoto K, Takeoka M, Kinoshita A, Kajimoto G, Nakayama T, Noda M: Novel pathways of oleic and cis-vaccenic acid biosynthesis by an enzymatic doublebond shifting reaction in higher plants. FEBS Lett 264: 228–230 (1990).

    Google Scholar 

  25. Studier FW, Rosenberg AH, Dunn JJ, Dubendorff JW: Use of T7 RNA polymerase to direct expression of cloned genes. Meth Enzymol 185: 60–89 (1990).

    Google Scholar 

  26. Thompson GA, Scherer DE, Foxall-Van Aken S, Kenny JW, Young HL, Shintani DK, Kridl JC, Knauf VC: Primary structures of the precursor and mature forms of stearoyl-acyl carrier protein desaturase from safflower embryos and requirement of ferredoxin for enzyme activity. Proc Natl Acad Sci USA 88: 2578–2582 (1991).

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA

    Edgar B. Cahoon* & John Shanklin

  2. Department of Biotechnology Research, Pioneer Hi-Bred International, Inc., Johnston, IA, 50131, USA

    Sean J. Coughlan

Authors
  1. Edgar B. Cahoon*
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sean J. Coughlan
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. John Shanklin
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Cahoon*, E.B., Coughlan, S.J. & Shanklin, J. Characterization of a structurally and functionally diverged acyl-acyl carrier protein desaturase from milkweed seed. Plant Mol Biol 33, 1105–1110 (1997). https://doi.org/10.1023/A:1005821007291

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1005821007291

Search

Navigation