Cryphonectria nitschkei virus 1 structure shows that the capsid protein of chrysoviruses is a duplicated helix-rich fold conserved in fungal double-stranded RNA viruses

5 p.-3 fig.Cryoelectron microscopy reconstruction of Cryphonectria nitschkei virus 1, a double-stranded RNA (dsRNA) virus, shows that the capsid protein (60 copies/particle) is formed by a repeated helical core, indicative of gene duplication. This unusual organization is common to chrysoviruses. The arrangement of many of these putative α-helices is conserved in the totivirus L-A capsid protein, suggesting a shared motif. Our results indicate that a 120-subunit T=1 capsid is a conserved architecture that optimizes dsRNA replication and organization. © 2012, American Society for MicrobiologyThis work was supported by grants from the Spanish Ministry of Science and Innovation (BFU2011-25902 to J.R.C. and BFU2011-29038 to J.L.C.), the NIH Intramural Research Program with support from the Center for Information Technology (to B.T.), and the Kentucky Science& Engineering Foundation (to S.A.G.)Peer reviewe