Identification, characterization, and expression of diacylgylcerol acyltransferase type-1 from Chlorella vulgaris

verfasst von

Linda Kirchner, Alison Wirshing, Lutfiye Kurt, Thomas Reinard, James Glick, Erin J. Cram, Hans-Jörg Jacobsen, Carolyn W.T. Lee-Parsons

Abstract

The green microalga Chlorella vulgaris can be induced to rapidly accumulate oil (40% by dry weight) with a biodiesel profile that is high in saturated and monounsaturated fatty acids. In this study, we sequenced the diacylglycerol acyltransferase type-1 from C. vulgaris (CvuDGAT1), which catalyzes the last step in triacylglycerol (TAG) biosynthesis, and characterized this protein using bioinformatics and functional expression assays in a yeast mutant. The CvuDGAT1 protein (460aa) shares motifs characteristic of other plant and microalga DGAT1s, including the binding domains for the acyl-CoA and diacylglycerol substrates and the putative active site. In addition, we report the first putative tertiary structure of DGAT1. This model shows that CvuDGAT1 is integrated into the ER membrane and predicts the proximity of the substrate-binding domains and the active site, despite being widely separated in the protein sequence. We also demonstrate CvuDGAT1's function in TAG biosynthesis by expressing the gene and restoring oil levels in a non-oil-producing yeast mutant. Interestingly, unlike Chlamydomonas reinhardtii, the CvuDGAT1 gene is constitutively expressed at high levels and may contribute to this species' ability to accumulate high levels of oil (i.e. 40% by dry weight).

Organisationseinheit(en)

Institut für Pflanzengenetik
Abteilung Pflanzenbiotechnologie

Externe Organisation(en)

Northeastern University

Typ

Artikel

Journal

Algal Research

Band

13

Seiten

167-181

Anzahl der Seiten

15

ISSN

2211-9264

Publikationsdatum

01.2016

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Agronomie und Nutzpflanzenwissenschaften

Elektronische Version(en)

https://doi.org/10.1016/j.algal.2015.10.017 (Zugang: Geschlossen)
https://doi.org/10.1016/j.algal.2016.02.010 (Zugang: Geschlossen)