Novel "extended sequons" of human N-glycosylation sites improve the precision of qualitative predictions: an alignment-free study of pattern recognition using ProtDCal protein features

N-Glycosylation is a common post-translational modification that plays an important role in the proper folding and function of many proteins. This modification is largely dependent on the presence of a sequence motif called a "sequon" defined as Asn-Xxx-Ser/Thr. However, evidence has shown that the presence of such a "sequon" is insufficient to determine the occurrence of N-glycosylation with high precision. This study aims to elucidate patterns that can more accurately predict N-glycosylation sites in human proteins. The novel motifs are evaluated using benchmarking data from 188 organisms. Performance is largely sustained compared to the human data, which validates the robustness of the novel extracted "extended sequons". We, therefore, introduce new knowledge about sequence-related factors that control N-glycosylation.