5OGL

Structure of bacterial oligosaccharyltransferase PglB in complex with an acceptor peptide and an lipid-linked oligosaccharide analog

Summary for 5OGL

• Entry DOI: 10.2210/pdb5ogl/pdb
• Descriptor: Undecaprenyl-diphosphooligosaccharide--protein glycotransferase, Substrate mimicking peptide, MANGANESE (II) ION, ... (6 entities in total)
• Functional Keywords: oligosaccharyltransferase, complex, protein n-glycosylation, bacteria, membrane protein
• Biological source: Campylobacter lari (strain RM2100 / D67 / ATCC BAA-1060); More
• Cellular location: Cell inner membrane ; Multi- pass membrane protein : B9KDD4
• Total number of polymer chains: 2
• Total formula weight: 84675.63

Authors

Napiorkowska, M.,Boilevin, J.,Sovdat, T.,Darbre, T.,Reymond, J.-L.,Aebi, M.,Locher, K.P. (deposition date: 2017-07-13, release date: 2017-10-25, Last modification date: 2024-01-17)

Primary citation

Napiorkowska, M.,Boilevin, J.,Sovdat, T.,Darbre, T.,Reymond, J.L.,Aebi, M.,Locher, K.P.
Molecular basis of lipid-linked oligosaccharide recognition and processing by bacterial oligosaccharyltransferase.
Nat. Struct. Mol. Biol., 24:1100-1106, 2017

PubMed Abstract: Oligosaccharyltransferase (OST) is a membrane-integral enzyme that catalyzes the transfer of glycans from lipid-linked oligosaccharides (LLOs) onto asparagine side chains, the first step in protein N-glycosylation. Here, we report the X-ray structure of a single-subunit OST, PglB from Campylobacter lari, trapped in an intermediate state bound to an acceptor peptide and a synthetic LLO analog. The structure reveals the role of the external loop EL5, present in all OST enzymes, in substrate recognition. Whereas the N-terminal half of EL5 binds LLO, the C-terminal half interacts with the acceptor peptide. The glycan moiety of LLO must thread under EL5 to access the active site. Reducing EL5 mobility decreases the catalytic rate of OST when full-size heptasaccharide LLO is provided, but not for a monosaccharide-containing LLO analog. Our results define the chemistry of a ternary complex state, assign functional roles to conserved OST motifs, and provide opportunities for glycoengineering by rational design of PglB.

PubMed: 29058712
DOI: 10.1038/nsmb.3491

Experimental method

X-RAY DIFFRACTION (2.7 Å)