摘要：SummaryViruses interact extensively with the host molecular machinery, but the underlying mechanisms are poorly understood. Bacteriophage T7 recruits the small protein thioredoxin of theEscherichia colihost as an essential processivity factor for the viral DNA polymerase. We challenged the phage to propagate in a host in which thioredoxin had been extensively modified to hamper its recruitment. The virus adapted to the engineered host without losing the capability to propagate in the original host, but no genetic mutations were fixed in the thioredoxin binding domain of the viral DNA polymerase. Virus adaptation correlated with mutations in the viral RNA polymerase, supporting that promiscuous thioredoxin recruitment was enabled by phenotypic mutations caused by transcription errors. These results point to a mechanism of virus adaptation that may play a role in cross-species transmission. We propose that phenotypic mutations may generally contribute to the capability of viruses to evade antiviral strategies.Graphical abstractDisplay OmittedHighlights•Phage adapts to a host modified to hinder the essential recruitment of a host protein•No genetic mutations are fixed at the engineered virus-host interaction interface•Adaptation is likely linked to phenotypic mutations caused by transcription errors•Sub-genomic RNAs may enable this kind of adaptation mechanism in coronavirusesBiological Sciences; Microbiology; Virology
