Alterations detected in the K22 resistant variants of HCoV-229E.

aDetected by comparison of the nucleotide sequences of HCoV-229E subjected to 10–13 passages in the presence of K22 including its plaque purified variants A-R with those of initial virus or mock-passaged virus (accession number KF293665).bPlaque purified HCoV-229E that served as initial material for the virus passages.cIC50 (µM).dFold resistance to K22 as related to initial virus is shown in parentheses.eVirus preparation and its plaque purified variants M-R obtained in separate K22 selection experiment.fThe virus used for preparation of recombinant nsp6 mutants.gK22 resistant recombinant viruses.