Novel glycoproteins of the halophilic archaeon Haloferax volcanii

Archaea possess many eukaryote-like properties, including the ability to glycosylate proteins. Using oligosaccharide staining and lectin binding, this study revealed the existence of several glycosylated Haloferax volcanii membrane proteins, besides the previously reported surface layer (S-layer) glycoprotein. While the presence of glycoproteins in archaeal S-layers and flagella is well-documented, few archaeal glycoproteins that are not part of these structures have been reported. The glycosylated 150, 98, 58 and 54 kDa protein species detected were neither precursors nor breakdown products of the 190 kDa S-layer glycoprotein. Furthermore, these novel glycoproteins were outwardly oriented and intimately associated with the membrane.