FIGURE 1.

Coronavirus classification and structure. (A) Coronavirus classification: the seven recognized HCoVs are shown in green and red. Red bind HCoVs to the ACE2 host receptor. (B) The SARS‐CoV‐2 structure scheme; the “Desiree Ho,” an Innovative Genomics Institute "illustrator is adapted from the https://innovativegenomics.org/free-covid-19-illustrations/. (C) Cartoon illustrates main features and the SARS‐CoV‐2 S protein trimeric structure. (D) SARS‐CoV‐2 schemas (top) and S‐protein (bow); NCBI (NC 045512.2) and Expasy (https://covid-19.uniprot.org/uniprotkb/P0DTC2) schematic annotations have been updated respectively) (adapted from Mittal et al ¹⁵ without modifications)

Abbreviations: CTD, C‐terminal domain; E, envelope; HCoV, human coronavirus; HR1/2, heptad repeat 1/2; M, membrane; N, nuclear‐capside; NSP, nonstructural protein; NTD, n‐terminal domain; orf, open reading framework; RBD, receptor‐binding motif; RdRp, RNA‐dependent polymerase, protein, spike protein; SARS‐CoV‐2, severe acute respiratory syndrome