title: Occurrence of L-iduronic acid and putative D-glucuronyl C5-epimerases in prokaryotes.
abstract: Glycosaminoglycans (GAGs) are polysaccharides that are typically present in a wide diversity of animal tissue. Most common GAGs are well-characterized and pharmaceutical applications exist for many of these compounds, e.g. heparin and hyaluronan. In addition, also bacterial glycosaminoglycan-like structures exist. Some of these bacterial GAGs have been characterized, but until now no bacterial GAG has been found that possesses the modifications that are characteristic for many of the animal GAGs such as sulfation and C5-epimerization. Nevertheless, the latter conversion may also occur in bacterial and archaeal GAGs, as some prokaryotic polysaccharides have been demonstrated to contain L-iduronic acid. However, experimental evidence for the enzymatic synthesis of L-iduronic acid in prokaryotes is as yet lacking. We therefore performed an in silico screen for D-glucuronyl C5-epimerases in prokaryotes. Multiple candidate C5-epimerases were found, suggesting that many more microorganisms are likely to exist possessing an L-iduronic acid residue as constituent of their cell wall polysaccharides.
authors.affiliation: Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands. John.Raedts@wur.nl
authors.forename: John
authors.initials: J
authors.lastname: Raedts
authors.forename: Servé W M
authors.initials: SW
authors.lastname: Kengen
authors.forename: John
authors.initials: J
authors.lastname: van der Oost
mesh_terms: D000595:Amino Acid Sequence; D001105:Archaea / Q000737:chemistry / Q000201:enzymology*; D001419:Bacteria / Q000737:chemistry / Q000201:enzymology*; D002238:Carbohydrate Epimerases / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006025:Glycosaminoglycans / Q000737:chemistry; D006493:Heparin / Q000737:chemistry; D007067:Iduronic Acid / Q000737:chemistry*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D006025:Glycosaminoglycans; D007067:Iduronic Acid; D020723:Glucuronic Acid; D006493:Heparin; D002238:Carbohydrate Epimerases; C019591:heparosan N-sulfate D-glucuronosyl 5-epimerase