Molecular cloning and functional expression of the gene for a cotton Delta-12 fatty acid desaturase (FAD2).
Two overlapping genomic clones spanning 16.5 kb of cotton DNA were found to encompass a Delta-12 fatty acid desaturase (FAD2-3) gene. A partial FAD2-3 cDNA clone was also analyzed. The FAD2-3 gene has one large intron of 2967 bp entirely within its 5'-untranslated region, only 12 bp upstream from the ATG initiation codon. Several potential promoter elements, including several light-responsive motifs, occur in the 5'-flanking region. The continuous FAD2-3 coding region is 1155 bp and would encode a protein of 384 amino acids. The polypeptide has four putative membrane-spanning helices, indicative of an integral membrane protein, and is most likely localized in the endoplasmic reticulum. Yeast cells transformed with a plasmid construct containing the cotton FAD2-3 coding region accumulate an appreciable amount of linoleic acid (18:2), not normally present in wild-type yeast cells, indicating that the gene encodes a functional FAD2 enzyme.
Pirtle
I L
IL
Department of Biological Sciences, University of North Texas, Denton, TX 76203-5220, USA. pirtle@unt.edu
Kongcharoensuntorn
W
W
Nampaisansuk
M
M
Knesek
J E
JE
Chapman
K D
KD
Pirtle
R M
RM
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry; D044943:Fatty Acid Desaturases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D005786:Gene Expression Regulation; D003368:Gossypium / Q000201:enzymology / Q000235:genetics*; D019787:Linoleic Acid / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D008563:Membrane Lipids; D008565:Membrane Proteins; D010940:Plant Proteins; D004247:DNA; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase