Structure-guided identification of a new catalytic motif of oligosaccharyltransferase

Mayumi Igura, Nobuo Maita, Jun Kamishikiryo, Masaki Yamada, Takayuki Obita, Katsumi Maenaka, Daisuke Kohda

    Research output: Contribution to journalArticlepeer-review

    145 Citations (Scopus)


    Asn-glycosylation is widespread not only in eukaryotes but also in archaea and some eubacteria. Oligosaccharyltransferase (OST) catalyzes the co-translational transfer of an oligosaccharide from a lipid donor to an asparagine residue in nascent polypeptide chains. Here, we report that a thermophilic archaeon, Pyrococcus furiosus OST is composed of the STT3 protein alone, and catalyzes the transfer of a heptasaccharide, containing one hexouronate and two pentose residues, onto peptides in an Asn-X-Thr/Ser-motif- dependent manner. We also determined the 2.7-Å resolution crystal structure of the C-terminal soluble domain of Pyrococcus STT3. The structure-based multiple sequence alignment revealed a new motif, DxxK, which is adjacent to the well-conserved WWDYG motif in the tertiary structure. The mutagenesis of the DK motif residues in yeast STT3 revealed the essential role of the motif in the catalytic activity. The function of this motif may be related to the binding of the pyrophosphate group of lipid-linked oligosaccharide donors through a transiently bound cation. Our structure provides the first structural insights into the formation of the oligosaccharide-asparagine bond.

    Original languageEnglish
    Pages (from-to)234-243
    Number of pages10
    JournalEMBO Journal
    Issue number1
    Publication statusPublished - Jan 9 2008

    All Science Journal Classification (ASJC) codes

    • Neuroscience(all)
    • Molecular Biology
    • Biochemistry, Genetics and Molecular Biology(all)
    • Immunology and Microbiology(all)


    Dive into the research topics of 'Structure-guided identification of a new catalytic motif of oligosaccharyltransferase'. Together they form a unique fingerprint.

    Cite this