{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/7199903","sourcedb":"PMC","sourceid":"7199903","source_url":"https://www.ncbi.nlm.nih.gov/pmc/7199903","text":"Two sites on SARS-CoV-2 S are principally oligomannose-type: N234 and N709. The predominant oligomannose-type glycan structure observed across the protein, with the exception of N234, is Man5GlcNAc2 (Man, mannose; GlcNAc, N-acetylglucosamine), which demonstrates that these sites are largely accessible to α-1,2-mannosidases but are poor substrates for GlcNAcT-I, which is the gateway enzyme in the formation of hybrid- and complex-type glycans in the Golgi apparatus. The stage at which processing is impeded is a signature related to the density and presentation of glycans on the viral spike. For example, the more densely glycosylated spikes of HIV-1 Env and Lassa virus (LASV) GPC exhibit numerous sites dominated by Man9GlcNAc2 (21–24).","typesettings":[{"style":"subscript","span":{"begin":190,"end":191}},{"style":"subscript","span":{"begin":197,"end":198}},{"style":"subscript","span":{"begin":725,"end":726}},{"style":"subscript","span":{"begin":732,"end":733}},{"style":"italic","span":{"begin":735,"end":737}},{"style":"italic","span":{"begin":738,"end":740}}]}