title: Syntheses of 2-keto-3-deoxy-D-xylonate and 2-keto-3-deoxy-L-arabinonate as stereochemical probes for demonstrating the metabolic promiscuity of Sulfolobus solfataricus towards D-xylose and L-arabinose.
abstract: Practical syntheses of 2-keto-3-deoxy-D-xylonate (D-KDX) and 2-keto-3-deoxy-L-arabinonate (L-KDA) that rely on reaction of the anion of ethyl 2-[(tert-butyldimethylsilyl)oxy]-2-(dimethoxy phosphoryl) acetate with enantiopure glyceraldehyde acetonide, followed by global deprotection of the resultant O-silyl-enol esters, have been developed. This has enabled us to confirm that a 2-keto-3-deoxy-D-gluconate aldolase from the archaeon Sulfolobus solfataricus demonstrates good activity for catalysis of the retro-aldol cleavage of both these enantiomers to afford pyruvate and glycolaldehyde. The stereochemical promiscuity of this aldolase towards these enantiomeric aldol substrates confirms that this organism employs a metabolically promiscuous pathway to catabolise the C5-sugars D-xylose and L-arabinose.
authors: Department of Chemistry, University of Bath, Bath BA2 7AY, UK.
authors: Robert M
authors: RM
authors: Archer
authors: Sylvain F
authors: SF
authors: Royer
authors: William
authors: W
authors: Mahy
authors: Caroline L
authors: CL
authors: Winn
authors: Michael J
authors: MJ
authors: Danson
authors: Steven D
authors: SD
authors: Bull
mesh_terms: D000446:Aldehyde-Lyases / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D001089:Arabinose / Q000737:chemistry* / Q000378:metabolism*; D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D005942:Gluconates / Q000737:chemistry*; D008958:Models, Molecular; D013400:Sugar Acids / Q000138:chemical synthesis* / Q000737:chemistry; D048229:Sulfolobus solfataricus / Q000737:chemistry* / Q000378:metabolism*; D014994:Xylose / Q000737:chemistry* / Q000378:metabolism*
chemical_list: C583633:2-keto-3-deoxy-D-xylonate; D002241:Carbohydrates; D005942:Gluconates; D013400:Sugar Acids; C045553:2-deoxygluconic acid; C010412:2-keto-3-deoxy-L-arabonate; D014994:Xylose; D001089:Arabinose; C021470:2-keto-3-deoxygluconate aldolase; D000446:Aldehyde-Lyases