A unique fungal lysine biosynthesis enzyme shares a common ancestor with tricarboxylic acid cycle and leucine biosynthetic enzymes found in diverse organisms
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Fungi have evolved a unique α-amino-adipate pathway for lysine biosynthesis. The fungal-specific enzyme homoaconitate hydratase from this pathway is moderately similar to the aconitase-family proteins from a diverse array of taxonomic groups, which have varying modes of obtaining lysine. We have used the similarity of homoaconitate hydratase to isopropylmalate isomerase (serving in leucine biosynthesis), aconitase (from the tricarboxylic acid cycle), and ironresponsive element binding proteins (cytosolic aconitase) from fungi and other eukaryotes, eubacteria, and archaea to evaluate possible evolutionary scenarios for the origin of this pathway. Refined sequence alignments show that aconitase active site residues are highly conserved in each of the enzymes, and intervening sequence sites are quite dissimilar. This pattern suggests strong purifying selection has acted to preserve the aconitase active site residues for a common catalytic mechanism; numerous other substitutions occur due to adaptive evolution or simply lack of functional constraint. We hypothesize that the similarities are the remnants of an ancestral gene duplication, which may not have occurred within the fungal lineage. Maximum likelihood, neighbor joining, and maximum parsimony phylogenetic comparisons show that the a-aminoadipate pathway enzyme is an outgroup to all aconitase family proteins for which sequence is currently available.
Key wordsHomoaconitate hydratase Homoaconitase Lysine biosynthesis a-Aminoadipate pathway Molecular evolution Amino acid metabolism Gene duplication Adaptive evolution Evolutionary origin
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- Bhattacharjee JK (1992) Evolution of the a-aminoadipate pathway for the synthesis of lysine in fungi. In: Mortlock RP (ed) The Evolution of metabolic function. CRC Press, LondonGoogle Scholar
- Bult CJ, White O, Olsen GJ, Zhou L, Fleischmann RD, Sutton GG, Blake JA, FitzGerald LM, Clayton RA, Gocayne JD, Kerlavage AR, Dougherty BA, Tomb J-F, Adams MD, Reich CI, Overbeek R, Kirkness EF, Weinstock KG, Merrick JM, Glodek A, Scott JL, Geoghagen NSM, Weidman JF, Fuhrmann JL, Presley EA, Nguyen D, Utterback TR, Kelley JM, Peterson JD, Sadow PW, Hanna MC, Cotton MD, Hurst MA, Roberts KM, Kaine BP, Borodovsky M, Klenk H-P, Fraser CM, Smith HO, Woese CR, Venter JC (1996) Complete genome sequence of the methanogenic archaeon, Metha- nococcus jannaschii. Science 273 (5278):1058–1073PubMedCrossRefGoogle Scholar
- Dayhoff MO, Schwartz RM, Orcutt BC (1978) A model of evolutionary change in proteins. In Dayhoff MO (ed) Atlas of protein sequence and structure, vol 5, suppl 3. Natl Biomed Res Found., Silver Spring, MD, pp 345–352Google Scholar
- Felsenstein J (1993) PHYLIP (phylogeny inference package) version 3.572. Distributed by the author. Department of Genetics, University of Washington, Seattle, WAGoogle Scholar
- Strassman M (1964) Lysine biosynthesis in yeast. Abstr 6th Intern Congr Biochem 5:373–374Google Scholar
- Strassman M (1964) Lysine Biosynthesis in yeast. Abstr 6th Intern Congr Biochem 5:373–374Google Scholar
- Strimmer K, von Haeseler A (1996) Quartet puzzling: a quartet maximum likelihood method for reconstructing tree topologies. Mol Biol Evol 13:964–969Google Scholar
- Swofford DL (1993) PAUP, Version 3.1. Illinois Natural History Survey, Champaign, ILGoogle Scholar
- Vogel HJ (1965) Lysine biosynthesis and evolution. In: V Bryson (ed) Evolving genes and proteins. Academic Press, New York, pp 25–40Google Scholar