Now in the second step,
attachment
2. En-bloc transfer of the
oligosaccharide to the
protein
• One step transfer, catalyzed by
oligosaccharyl transferase,
which is bound to the membrane
at the translocator.
• Covalently attached to certain
asparagines in the polypeptide
chain (said to be “N-linked”
glycosylation).
• Attaches to NH2 side chain of
Asn but only in the context:
Asn-x-Ser  or   Asn-x-Thr