Which glycosylation type involves attachment to tryptophan residues?
Among glycosylation classes, attachment via carbon-carbon bond to tryptophan indole ring is chemically distinct and relatively rare. C-mannosylation involves α-D-mannopyranose linked to carbon-2 of indole of tryptophan within consensus W-X-X-W or W-X-X-C motif, catalyzed co-translationally inside ER lumen by multi-pass membrane enzymes DPY19L1 through L4 using dolichol-phosphate-mannose as high-energy donor substrate assembled on ER membrane. Modification increases hydrophobicity locally, stabilizes beta-propeller and thrombospondin type 1 repeat folds found in properdin, F-spondin, mindin, AD
Ref: Buettner et al., Mol Cell 72: 2018, C-Mannosylation of Tryptophan by DPY19.
