Dolichol-linked oligosaccharide selection by the oligosaccharyltransferase in protist and fungal organisms
UMass Chan Affiliations
Department of Biochemistry and Molecular PharmacologyDocument Type
Journal ArticlePublication Date
2007-04-04Keywords
AnimalsBinding Sites
Cryptococcus neoformans
Dolichol
Entamoeba histolytica
Fungal Proteins
Hexosyltransferases
Kinetics
Mannose
Membrane Proteins
Oligosaccharides
Protozoan Proteins
Saccharomyces cerevisiae
Substrate Specificity
Trichomonas vaginalis
Trypanosoma cruzi
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
The dolichol-linked oligosaccharide Glc3Man9GlcNAc2-PP-Dol is the in vivo donor substrate synthesized by most eukaryotes for asparagine-linked glycosylation. However, many protist organisms assemble dolichol-linked oligosaccharides that lack glucose residues. We have compared donor substrate utilization by the oligosaccharyltransferase (OST) from Trypanosoma cruzi, Entamoeba histolytica, Trichomonas vaginalis, Cryptococcus neoformans, and Saccharomyces cerevisiae using structurally homogeneous dolichol-linked oligosaccharides as well as a heterogeneous dolichol-linked oligosaccharide library. Our results demonstrate that the OST from diverse organisms utilizes the in vivo oligo saccharide donor in preference to certain larger and/or smaller oligosaccharide donors. Steady-state enzyme kinetic experiments reveal that the binding affinity of the tripeptide acceptor for the protist OST complex is influenced by the structure of the oligosaccharide donor. This rudimentary donor substrate selection mechanism has been refined in fungi and vertebrate organisms by the addition of a second, regulatory dolichol-linked oligosaccharide binding site, the presence of which correlates with acquisition of the SWP1/ribophorin II subunit of the OST complex.Source
J Cell Biol. 2007 Apr 9;177(1):29-37. Epub 2007 Apr 2. Link to article on publisher's siteDOI
10.1083/jcb.200611079Permanent Link to this Item
http://hdl.handle.net/20.500.14038/38415PubMed ID
17403929Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1083/jcb.200611079