The genomic diversity of SARS-CoV-2 has been a focus during the ongoing COVID-19 pandemic. Here, we analyzed the distribution and character of emerging mutations in a data set comprising more than 95,000 virus genomes covering eight major SARS-CoV-2 lineages in the GISAID database, including genotypes arising during COVID-19 therapy. Globally, the C>U transitions and G>U transversions were the most represented mutations, accounting for the majority of single-nucleotide variations. Mutational spectra were not influenced by the time the virus had been circulating in its host or medical treatment. At the amino acid level, we observed about a 2-fold excess of substitutions in favor of hydrophobic amino acids over the reverse. However, most mutations constituting variants of interests of the S-protein (spike) lead to hydrophilic amino acids, counteracting the global trend. The C>U and G>U substitutions altered codons towards increased amino acid hydrophobicity values in more than 80% of cases. The bias is explained by the existing differences in the codon composition for amino acids bearing contrasting biochemical properties. Mutation asymmetries apparently influence the biochemical features of SARS CoV-2 proteins, which may impact protein–protein interactions, fusion of viral and cellular membranes, and virion assembly.
【저자키워드】 Evolution, SARS-CoV-2, coronavirus, Genetic variation, mutability, apolipoprotein B mRNA editing enzyme (APOBEC), amino acid hydrophobicity, 【초록키워드】 COVID-19, SARS CoV-2, Treatment, therapy, Mutation, COVID-19 pandemic, mutations, Proteins, virus, variants, Viral, Genotype, substitutions, amino acids, hydrophobicity, variants of interest, COVID-19 therapy, variations, genotypes, distribution, fusion, genomic, Amino acid, S-protein, GISAID database, protein–protein interactions, lead, focus, data set, biochemical, SARS CoV, favor, Substitution, codon, circulating, virion assembly, cellular membranes, Codons, virus genome, SARS-CoV-2 lineage, character, Host, feature, analyzed, eight, arising, majority, explained, hydrophilic, G>U transversion, hydrophobic amino acid, single-nucleotide, 【제목키워드】 lead, asymmetry, Increased, the SARS-CoV-2,