Fig. 1

SARS-CoV-2 spike glycoprotein polybasic furin cleavage site. Fragment of a multiple sequence alignment covering the SARS-CoV-2 spike glycoprotein polybasic furin cleavage site. The first line at the top indicates the positions, in a P14-P6’ nomenclature, of the canonical structure of a furin site in a given protein. The specific cleavage site is between positions P1 and P1’. The core regions is between positions P6–P2’ and there are two flanking solvent accessible regions: P7–P14 and P3’–P6’ [15]. Part A. Fragment of the protein multiple sequence aligment including Laos bat Rhinolophus coronaviruses BANAL-52 (GISAID, EPI_ISL_4302644: 21512–25,321), BANAL-103 (GISAID, EPI_ISL_4302645: 21498–25,294), BANAL-236 (GISAID, EPI_ISL_4302647: 21538–25,344), Vietnam bat Rhinolophus pusillus Rp22DB159 coronavirus (GenBank: WLJ60537.1 coded by OR233302.1:21533..25342 genome), Bat coronavirus RaTG13 (GenBank: QHR63300.2 coded by MN996532.2: 21560..25369 genome) and the reference SARS-CoV-2 sequences (isolates Wuhan-Hu-1 and WH04) [14]. The SARS-CoV-2 polybasic insert (PRRA) is denoted in bold. Strictly conserved amino acids are denoted by *. The amino acid position is indicated at the numbers on the right. Part B. Fragment of the codon alignment. For simplicity, from the Laos coronavirus only the BANAL-52 sequence has been included. The two possibles 12 nucleotide fragment encoding PRRA inserted within the S680 codon are highlighted in yellow and orange, respectively. The S680 TCA codon is denoted in green. The differences at the third codon position are denoted in gray. The protein and genome sequence position is indicated at the numbers on the right