UDP-xylose and UDP-galactose synthesis in Trichomonas vaginalis.
The presence of xylose and galactose residues in the structure of trichomonad lipoglycans was indicated by previous studies and the modification of any glycoconjugate with either monosaccharide requires the respective presence of the nucleotide sugars, UDP-xylose and UDP-galactose. Biosynthesis of UDP-xylose de novo is mediated by UDP-xylose synthase (UXS; UDP-glucuronic acid decarboxylase), which converts UDP-glucuronic acid to UDP-xylose, whereas UDP-galactose can be generated from UDP-glucose by UDP-galactose epimerases (GalE). Trichomonas vaginalis cDNAs, encoding proteins with homology to these enzymes from other eukaryotes, were isolated. The recombinant T. vaginalis UDP-xylose synthase and UDP-galactose epimerase were expressed in Escherichia coli and tested via high pressure liquid chromatography to demonstrate their enzymatic activities. Thereby, in this first report on enzymes involved in glycoconjugate biosynthesis in this organism, we demonstrate the existence of xylose and galactose synthesising pathways in T. vaginalis.
Department für Chemie, Universität für Bodenkultur, A-1190 Wien, Austria.
Andrea F N
AF
Rosenberger
Lydia
L
Hangelmann
Andreas
A
Hofinger
Iain B H
IB
Wilson
D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D014246:Trichomonas vaginalis / Q000378:metabolism*; D014534:UDPglucose 4-Epimerase / Q000235:genetics / Q000378:metabolism; D014531:Uridine Diphosphate Galactose / Q000378:metabolism*; D014540:Uridine Diphosphate Xylose / Q000378:metabolism*
D014531:Uridine Diphosphate Galactose; D014540:Uridine Diphosphate Xylose; D002262:Carboxy-Lyases; C023257:UDPglucuronate decarboxylase; D014534:UDPglucose 4-Epimerase