Iduronic acid: constituent of sulphated dolichyl phosphate oligosaccharides in halobacteria

Abstract

The occurrence of iduronic acid in the cell surface glycoprotein of halobacteria is described. This hexuronic acid is not only found in protein-linked oligosaccharides in halobacteria but does also exist in the corresponding dolichol-linked precursors. These findings were unexpected, as iduronic acid is a typical constituent of animal glycosaminoglycans, and its biosynthesis is so far known to occur by epimerization of a glucuronic acid residue within the completed carbohydrate chain linked to protein.