HPhosphate(P)Dolichol二Phase oneOManGIcNAcGlcGDP-ManUDP-GIcNAcCytoplasmDolichol-P0eePhase twoDolichol-pDolichol-PProteinacceptorLumenofGlcManEndoplasmicreticulum福福888888Dolichol-PManDolichol-P Glc大10001808180808 00000.CytoplasmGDP-ManUDP-GIc
Phase one! Phase two!
1.4 The dolichol-linked precursoroligosaccharide is transferred toasparagine residues of polypeptides
1.4 The dolichol-linked precursor oligosaccharide is transferred to asparagine residues of polypeptides
Three conditions for sugar-attached Asparagineresidue· They must be located in a specific sequencecontext within the primary structure of theprotein: They must be located appropriately in the 3Dstructureoftheprotein. They must be found in the correct intracellularcompartment
Three%condi+ons%for%sugar1a2ached%Asparagine% residue%% • They#must#be#located#in#a#specific#sequence# context#within#the#primary#structure#of#the# protein# • They#must#be#located#appropriately#in#the#3D# structure#of#the#protein# • They#must#be#found#in#the#correct#intracellular# compartment#
OAsn-Xaa-Thr orAsn-Xaa-SerAsn-Xaa-CysOHOHNH2AsnOH00OHH30HCOHNH2NH2ThrSerCCHNOHNHOHSHProIS
Asn1Xaa1Thr%%or%Asn1Xaa1Ser Asn1Xaa1Cys Asn! Thr! Ser! Pro! Cys!
Hydrophilicity/energysense/proteinsurface/co-translational eventRibosomeCytoplasmmgmgm00001iuWOligosaccharyltransferaseLumen ofEndoplasmicreticulumAsn-X-Ser/ThrSignal000Dolichol●PhosphateOManGlcGlcNAcSequence
Hydrophilicity / energy sense / protein surface ! / co-translational event!