It is now clear that N-glycosylation, the covalent linkage of glycans to select asparagine residues of target proteins, is a post-translational modification that occurs across evolution. While understanding of the eukaryal and bacterial versions of this universal protein-processing event is relatively advanced, far less is known of N-glycosylation in Archaea. This, despite the fact that N-glycosylation is seemingly widespread in Archaea and that archaeal N-linked glycans present diversity in composition and structure not seen elsewhere. Relying on the halophilic archaea Haloferax volcanii, originally isolated from the Dead Sea, as a model system, work in our group has tried to fill this void. Accordingly, bioinformatics, genetic, mass spectrometry and biochemical approaches have been employed to delineate the pathways used for the assembly of two distinct glycans N-linked to target proteins in Hfx. volcanii. The same general strategy is now being used to better understand N-glycosylation pathways in other Archaea. As such, our studies on archaeal N-glycosylation not only expand understanding of a universal post-translational modification, they also provide novel insight into life at extremes.
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