Host cell 核衣壳蛋白(N) 棘突蛋白(S) 99 RNA modifications detected using SARS-CoV-2 nanopore direct RNA sequencing RNA AAGAA 包膜蛋白(E) 膜蛋白(M) Envelope Protein ORF1ab Viral genomic RNA Membrane Protein AAGAA-type Canonical subgenomic RNAs modification cluster Nucleocapsid Protein 3a Spike Protein 6 7a Lipid Membrane 8 CE2 Noncanonical subgenomic RNAs Truncated fusion Frameshifted ORF tiatiit Body-to-body junction Host Cell