Characterization of a Type‐2 Diacylglycerol Acyltransferase from Haematococcus pluvialis Reveals Possible Allostery of the Recombinant Enzyme

• Author(s) / Creator(s)

  • Nguyen, Trinh
  • Xu, Yang
  • Abdel-Hameed, Mona
  • Sorensen, John L.
  • Singer, Stacy D.
  • Chen, Guanqun

• Haematococcus pluvialis is a green microalga used in the algal biotechnology industry that can accumulate considerable amounts of storage triacylglycerol (TAG) and astaxanthin, which is a high‐value carotenoid with strong antioxidant activity, under stress conditions. Diacylglycerol acyltransferase (DGAT) catalyzes the last step of the acyl‐CoA‐dependent TAG biosynthesis and appears to represent a bottleneck in algal TAG formation. In this study, putative H. pluvialis DGAT2 cDNA (HpDGAT2A, B, D and E) were identified from a transcriptome database and were subjected to sequence‐based in silico analyses. The coding sequences of HpDGAT2B, D, and E were then isolated and characterized through heterologous expression in a TAG‐deficient Saccharomyces cerevisiae strain H1246. The expression of HpDGAT2D allowed the recovery of TAG biosynthesis in this yeast mutant, and further in vitro enzymatic assays confirmed that the recombinant HpDGAT2D possessed strong DGAT activity. Interestingly, the recombinant HpDGAT2D displayed sigmoidal kinetics in response to increasing acyl‐CoA concentrations, which has not been reported in plant or algal DGAT2 in previous studies.

• Date created

  2019-12-26

• Subjects / Keywords

  • Haematococcus pluvialis
  • Triacylglycerol biosynthesis
  • Algae
  • Sigmoidal kinetics
  • Saccharomyces cerevisiae
  • DGAT

• Type of Item

  Article (Draft / Submitted)

• DOI

  https://doi.org/10.7939/r3-nh4z-8q95

• License

  This is the peer reviewed version of the following article: Nguyen, T., Xu, Y., Abdel‐Hameed, M., Sorensen, J. L., Singer, S. D., & Chen, G. (2019). Characterization of a Type‐2 Diacylglycerol Acyltransferase from Haematococcus pluvialis Reveals Possible Allostery of the Recombinant Enzyme. Lipids., which has been published in final form at https://doi.org/10.1002/lipd.12210. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.