title: The repertoire of desaturases and elongases reveals fatty acid variations in 56 eukaryotic genomes.
abstract: The repertoire of biosynthetic enzymes found in an organism is an important clue for elucidating the chemical structural variations of various compounds. In the case of fatty acids, it is essential to examine key enzymes that are desaturases and elongases, whose combination determine the range of fatty acid structures. We systematically investigated 56 eukaryotic genomes to obtain 275 desaturase and 265 elongase homologs. Phylogenetic and motif analysis indicated that the desaturases consisted of four functionally distinct subfamilies and the elongases consisted of two subfamilies. From the combination of the subfamilies, we then predicted the ability to synthesize six types of fatty acids. Consequently, we found that the ranges of synthesizable fatty acids were often different even between closely related organisms. The reason is that, as well as diverging into subfamilies, the enzymes have functionally diverged within the individual subfamilies. Finally, we discuss how the adaptation to individual environments and the ability to synthesize specific metabolites provides some explanation for the diversity of enzyme functions. This study provides an example of a potent strategy to bridge the gap from genomic knowledge to chemical knowledge.
authors.affiliation: Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Akiyasu C
authors.initials: AC
authors.lastname: Yoshizawa
authors.forename: Shujiro
authors.initials: S
authors.lastname: Okuda
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kuma
authors.forename: Susumu
authors.initials: S
authors.lastname: Goto
authors.forename: Minoru
authors.initials: M
authors.lastname: Kanehisa
mesh_terms: D000123:Acetyltransferases / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D044943:Fatty Acid Desaturases / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D000081031:Fatty Acid Elongases; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000737:chemistry; D005658:Fungi / Q000201:enzymology; D016678:Genome; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D010944:Plants / Q000201:enzymology
chemical_list: D005231:Fatty Acids, Unsaturated; D044943:Fatty Acid Desaturases; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases