title: Identification and functional analysis of delta-9 desaturase, a key enzyme in PUFA Synthesis, isolated from the oleaginous diatom Fistulifera.
abstract: Oleaginous microalgae are one of the promising resource of nonedible biodiesel fuel (BDF) feed stock alternatives. Now a challenge task is the decrease of the long-chain polyunsaturated fatty acids (PUFAs) content affecting on the BDF oxidative stability by using gene manipulation techniques. However, only the limited knowledge has been available concerning the fatty acid and PUFA synthesis pathways in microalgae. Especially, the function of Δ9 desaturase, which is a key enzyme in PUFA synthesis pathway, has not been determined in diatom. In this study, 4 Δ(9) desaturase genes (fD9desA, fD9desB, fD9desC and fD9desD) from the oleaginous diatom Fistulifera were newly isolated and functionally characterized. The putative Δ(9) acyl-CoA desaturases in the endoplasmic reticulum (ER) showed 3 histidine clusters that are well-conserved motifs in the typical Δ(9) desaturase. Furthermore, the function of these Δ(9) desaturases was confirmed in the Saccharomyces cerevisiae ole1 gene deletion mutant (Δole1). All the putative Δ(9) acyl-CoA desaturases showed Δ(9) desaturation activity for C16∶0 fatty acids; fD9desA and fD9desB also showed desaturation activity for C18∶0 fatty acids. This study represents the first functional analysis of Δ(9) desaturases from oleaginous microalgae and from diatoms as the first enzyme to introduce a double bond in saturated fatty acids during PUFA synthesis. The findings will provide beneficial insights into applying metabolic engineering processes to suppressing PUFA synthesis in this oleaginous microalgal strain.
authors.affiliation: Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan ; JST, CREST, Sanbancho 5, Chiyoda-ku, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Muto
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kubota
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Akira
authors.initials: A
authors.lastname: Satoh
authors.forename: Mitsufumi
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yoshino
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000595:Amino Acid Sequence; D017377:Diatoms / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013230:Stearoyl-CoA Desaturase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D013230:Stearoyl-CoA Desaturase
references.citation: Nat Methods. 2011 Sep 29;8(10):785-6
references.pmid: 21959131
references.citation: PLoS One. 2012;7(7):e40751
references.pmid: 22792403
references.citation: Photosynth Res. 2011 Sep;109(1-3):223-9
references.pmid: 21290260
references.citation: BMC Bioinformatics. 2008 Sep 23;9:393
references.pmid: 18811941
references.citation: Eur J Biochem. 2002 Aug;269(16):4105-13
references.pmid: 12180987
references.citation: J Mol Biol. 2000 Jul 21;300(4):1005-16
references.pmid: 10891285
references.citation: J Biosci Bioeng. 2014 Jun;117(6):720-4
references.pmid: 24388444
references.citation: Mol Plant Microbe Interact. 2011 Apr;24(4):506-15
references.pmid: 21117867
references.citation: J Lipid Res. 2008 Jan;49(1):183-91
references.pmid: 17921532
references.citation: Plant Mol Biol. 1997 Apr;33(6):1105-10
references.pmid: 9154992
references.citation: Can J Microbiol. 1962 Apr;8:229-39
references.pmid: 13902807
references.citation: PLoS One. 2011;6(10):e25851
references.pmid: 22043295
references.citation: Science. 2004 Oct 1;306(5693):79-86
references.pmid: 15459382
references.citation: Nat Commun. 2012 Feb 21;3:686
references.pmid: 22353717
references.citation: Bioinformatics. 2001 Sep;17(9):849-50
references.pmid: 11590105
references.citation: Bioresour Technol. 2009 Jan;100(1):261-8
references.pmid: 18693011
references.citation: FEBS J. 2005 Jul;272(13):3401-12
references.pmid: 15978045
references.citation: Curr Genet. 1998 Mar;33(3):165-70
references.pmid: 9508790
references.citation: J Bacteriol. 1983 Jan;153(1):163-8
references.pmid: 6336730
references.citation: Appl Biochem Biotechnol. 2010 May;161(1-8):483-90
references.pmid: 19756412
references.citation: Biochemistry. 1994 Nov 1;33(43):12787-94
references.pmid: 7947684
references.citation: J Biol Chem. 1995 Dec 15;270(50):29766-72
references.pmid: 8530368
references.citation: Mar Biotechnol (NY). 2013 Feb;15(1):48-55
references.pmid: 22555859
references.citation: Plant Physiol. 2003 Apr;131(4):1648-60
references.pmid: 12692324
references.citation: J Lipid Res. 2006 Apr;47(4):700-4
references.pmid: 16443825
references.citation: J Biol Chem. 2011 Apr 15;286(15):12860-9
references.pmid: 21300802
references.citation: Bioresour Technol. 2013 Jun;137:132-8
references.pmid: 23584413
references.citation: J Mol Biol. 2001 Jan 19;305(3):567-80
references.pmid: 11152613
references.citation: Science. 1999 Aug 6;285(5429):901-6
references.pmid: 10436161
references.citation: Nature. 2008 Nov 13;456(7219):239-44
references.pmid: 18923393
references.citation: J Cell Biol. 1991 Nov;115(4):887-903
references.pmid: 1955461
references.citation: Microbiology (Reading). 2002 Jun;148(Pt 6):1725-1735
references.pmid: 12055292
references.citation: Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):2624-8
references.pmid: 1557366
references.citation: PLoS One. 2012;7(6):e38975
references.pmid: 22745696
references.citation: Plant Physiol. 2002 Aug;129(4):1732-43
references.pmid: 12177486
references.citation: Biotechnol Adv. 2007 May-Jun;25(3):294-306
references.pmid: 17350212