AUTHOR=Eichler Jerry , Arbiv Adi , Cohen-Rosenzweig Chen , Kaminski Lina , Kandiba Lina , Konrad Zvia 

TITLE=N-glycosylation in Haloferax volcanii: adjusting the sweetness

JOURNAL=Frontiers in Microbiology

VOLUME=4

YEAR=2013

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2013.00403

DOI=10.3389/fmicb.2013.00403

ISSN=1664-302X

ABSTRACT=<p>Long believed to be restricted to Eukarya, it is now known that cells of all three domains of life perform N-glycosylation, the covalent attachment of glycans to select target protein asparagine residues. Still, it is only in the last decade that pathways of N-glycosylation in Archaea have been delineated. In the haloarchaeon <italic>Haloferax volcanii</italic>, a series of Agl (<italic>a</italic>rchaeal <italic>gl</italic>ycosylation) proteins is responsible for the addition of an N-linked pentasaccharide to modified proteins, including the surface (S)-layer glycoprotein, the sole component of the surface layer surrounding the cell. The S-layer glycoprotein N-linked glycosylation profile changes, however, as a function of surrounding salinity. Upon growth at different salt concentrations, the S-layer glycoprotein is either decorated by the N-linked pentasaccharide introduced above or by both this pentasaccharide as well as a tetrasaccharide of distinct composition. Recent efforts have identified Agl5–Agl15 as components of a second <italic>Hfx. volcanii</italic> N-glycosylation pathway responsible for generating the tetrasaccharide attached to S-layer glycoprotein when growth occurs in 1.75 M but not 3.4 M NaCl-containing medium.</p>