title: A root-specific condensing enzyme from Lesquerella fendleri that elongates very-long-chain saturated fatty acids.
abstract: The LfKCS45 gene with a high sequence similarity to known 3-ketoacyl-CoA synthases of the membrane-bound fatty acid elongase was isolated from Lesquerella fendleri. The LfKCS45 gene has a 1464 bp open reading frame without introns, and is predicted to encode a polypeptide of 487 amino acids with an estimated molecular mass of 54.6 kD. High-stringency DNA blot analysis indicated that there were no closely related genes to LfKCS45 in the L. fendleri genome. Analysis of the fatty acid composition of transformed yeast revealed that expression of the LfKCS45 protein results in the synthesis of two novel very-long-chain fatty acids identified as C28:0 and C30:0. LfKCS45 was found to be not active with acyl-CoA substrates C16 to C24 in length. Reverse transcription-PCR experiments showed that the LfKCS45 gene is expressed only in L. fendleri root tips. Histochemical assays for GUS activity in Arabidopsis transformed with the LfKCS45 promoter-GUS fusion construct confirmed this expression pattern and demonstrated that LfKCS45 transcription is restricted to the cells of the lateral root cap.
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
authors.forename: Hangsik
authors.initials: H
authors.lastname: Moon
authors.forename: Gangamma
authors.initials: G
authors.lastname: Chowrira
authors.forename: Owen
authors.initials: O
authors.lastname: Rowland
authors.forename: Brenda J
authors.initials: BJ
authors.lastname: Blacklock
authors.forename: Mark A
authors.initials: MA
authors.lastname: Smith
authors.forename: Ljerka
authors.initials: L
authors.lastname: Kunst
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D019607:Brassicaceae / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D002849:Chromatography, Gas; D003001:Cloning, Molecular; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism*; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
chemical_list: D018744:DNA, Plant; D005227:Fatty Acids; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D005966:Glucuronidase; D003066:Coenzyme A Ligases; D000098859:Long-Chain-Fatty-Acid-CoA Ligase