01895nas a2200181   4500008004100000245013100041210006900172260001300241300001100254490000700265520119300272100002401465700002201489700002201511700002501533700002101558856013401579       2011                        eng d00aN-glycosylation efficiency is determined by the distance to the C-terminus and the amino acid preceding an Asn-Ser-Thr sequon.0 aNglycosylation efficiency is determined by the distance to the C  c2011 Jan  a179-860 v203 a<p>N-glycosylation is the most common and versatile protein modification. In eukaryotic cells, this modification is catalyzed cotranslationally by the enzyme oligosaccharyltransferase, which targets the &beta;-amide of the asparagine in an Asn-Xaa-Ser/Thr consensus sequon (where Xaa is any amino acid but proline) in nascent proteins as they enter the endoplasmic reticulum. Because modification of the glycosylation acceptor site on membrane proteins occurs in a compartment-specific manner, the presence of glycosylation is used to indicate membrane protein topology. Moreover, glycosylation sites can be added to gain topological information. In this study, we explored the determinants of N-glycosylation with the in vitro transcription/translation of a truncated model protein in the presence of microsomes and surveyed 25,488 glycoproteins, of which 2,533 glycosylation sites had been experimentally validated. We found that glycosylation efficiency was dependent on both the distance to the C-terminus and the nature of the amino acid that preceded the consensus sequon. These findings establish a broadly applicable method for membrane protein tagging in topological studies.</p>1 aBañó-Polo, Manuel1 aBaldin, Francesca1 aTamborero, Silvia1 aMarti-Renom, Marc, A1 aMingarro, Ismael  uhttps://www.clinbioinfosspa.es/content/n-glycosylation-efficiency-determined-distance-c-terminus-and-amino-acid-preceding-asn-ser