Assembly of complex viruses exemplified by a halophilic euryarchaeal virus
Luigi De Colibus, Elina Roine, Thomas S. Walter, Serban L. Ilca, Xiangxi Wang, Nan Wang, Alan M. Roseman, Dennis Bamford, Juha T. Huiskonen & David I. Stuart
Abstract
Many of the largest known viruses belong to the PRD1-adeno structural lineage characterised by conserved pseudo-hexameric capsomers composed of three copies of a single major capsid protein (MCP). Here, by high-resolution cryo-EM analysis, we show that a class of archaeal viruses possess hetero-hexameric MCPs which mimic the PRD1-adeno lineage trimer. These hetero-hexamers are built from heterodimers and utilise a jigsaw-puzzle system of pegs and holes, and underlying minor capsid proteins, to assemble the capsid laterally from the 5-fold vertices. At these vertices proteins engage inwards with the internal membrane vesicle whilst 2-fold symmetric horn-like structures protrude outwards. The horns are assembled from repeated globular domains attached to a central spine, presumably facilitating multimeric attachment to the cell receptor. Such viruses may represent precursors of the main PRD1-adeno lineage, similarly engaging cell-receptors via 5-fold spikes and using minor proteins to define particle size.
文章链接：https://www.nature.com/articles/s41467-019-09451-z
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