Rhamnose biosynthesis pathway supplies precursors for primary and secondary metabolism in Saccharopolyspora spinosa.
Rhamnose is an essential component of the insect control agent spinosad. However, the genes coding for the four enzymes involved in rhamnose biosynthesis in Saccharopolyspora spinosa are located in three different regions of the genome, all unlinked to the cluster of other genes that are required for spinosyn biosynthesis. Disruption of any of the rhamnose genes resulted in mutants with highly fragmented mycelia that could survive only in media supplemented with an osmotic stabilizer. It appears that this single set of genes provides rhamnose for cell wall synthesis as well as for secondary metabolite production. Duplicating the first two genes of the pathway caused a significant improvement in the yield of spinosyn fermentation products.
Madduri
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Dow AgroSciences LLC, Indianapolis, Indiana 46268, USA. kmmadduri@dowagro.com
Waldron
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Merlo
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D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D017353:Gene Deletion; D020440:Gene Duplication; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D018942:Macrolides; D008969:Molecular Sequence Data; D019998:Racemases and Epimerases / Q000235:genetics / Q000378:metabolism; D012210:Rhamnose / Q000096:biosynthesis* / Q000235:genetics; D016930:Saccharopolyspora / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018942:Macrolides; C114883:spinosyn A; D000429:Alcohol Oxidoreductases; C436311:NDP-4-keto-rhamnose 4'-ketoreductase; D005964:Glucosyltransferases; C436309:NDP-glucose synthase; D006836:Hydro-Lyases; C436310:NDP-glucose dehydratase; C022771:dTDPglucose 4,6-dehydratase; D019998:Racemases and Epimerases; C436308:NDP-4-keto-6-deoxy-D-glucose 3',5'-epimerase; D012210:Rhamnose