{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/7199903","sourcedb":"PMC","sourceid":"7199903","source_url":"https://www.ncbi.nlm.nih.gov/pmc/7199903","text":"Fig. 1  Expression and validation of the SARS-CoV-2 S glycoprotein.\n(A) Schematic representation of the SARS-CoV-2 S glycoprotein. The positions of N-linked glycosylation sequons (N-X-S/T, where X ≠ P) are shown as branches (N, Asn; X, any residue; S, Ser; T, Thr; P, Pro). Protein domains are illustrated: N-terminal domain (NTD), receptor binding domain (RBD), fusion peptide (FP), heptad repeat 1 (HR1), central helix (CH), connector domain (CD), and transmembrane domain (TM). (B) SDS–polyacrylamide gel electrophoresis analysis of the SARS-CoV-2 S protein (indicated by the arrowhead) expressed in human embryonic kidney (HEK) 293F cells. Lane 1: filtered supernatant from transfected cells; lane 2: flow-through from StrepTactin resin; lane 3: wash from StrepTactin resin; lane 4: elution from StrepTactin resin. (C) Negative-stain EM 2D class averages of the SARS-CoV-2 S protein. 2D class averages of the SARS-CoV-2 S protein are shown, confirming that the protein adopts the trimeric prefusion conformation matching the material used to determine the structure (4).","divisions":[{"label":"label","span":{"begin":0,"end":6}},{"label":"title","span":{"begin":8,"end":67}}],"typesettings":[{"style":"bold","span":{"begin":69,"end":70}},{"style":"bold","span":{"begin":482,"end":483}},{"style":"bold","span":{"begin":820,"end":821}},{"style":"italic","span":{"begin":1071,"end":1072}}],"project":"LitCovid-sample-PD-GlycoEpitope"}