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Fig. 2 | Biology Direct

Fig. 2

From: The multiple evolutionary origins of the eukaryotic N-glycosylation pathway

Fig. 2

Polyprenol-based glycosylation pathways (and GPI biosynthesis) colored according to detected homology groups. Horizontal lines represent ER membranes in the eukaryotes, plasma membranes in prokaryotes. Horizontal rectangles represent cytoplasmic glycosyltransferases (GTs) if they are below the membrane or lumen/periplasmic GTs if they are above the membrane. Vertical rectangles depict flippases or translocation mechanisms. Ovals represent the oligosaccharide transferases from the lipid carrier to the acceptor molecule. Diamonds portray proteins that are neither GTs nor translocases (e.g. acetyl or ethanolamine transferases in GPI biosynthesis). Extra shapes in the eukaryotic oligosaccharide transferases reflect the fact that these are complexes with many subunits. The cytoplasmic GTs depicted after a transfer to the acceptor molecule (e.g. Dpm1 and Alg5 in eukaryotic N-glycosylation) represent polyisoprenol-P-monosaccharide synthases tranfering single mannoses or glucoses to a lipid carrier to supply these sugars to the opposite side of the membrane. Proteins are colored according to the homology group to which they belong (as defined in Methods). Plain symbols represent proteins that were detected using the procedure described in Methods, whilst empty white shapes show more distant relationships that required bibliographic or extra analyses to be established. Empty transparent shapes represent the lack of detection of any homologues in the dataset

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