Single/double-jelly roll vertical
Topology
The strands are traditionally labeled B through I for the historical reason that the first solved structure, the jelly-roll capsid protein of the tomato bushy stunt virus, had an additional strand A outside the common core of the fold. The sheets are composed of strands BIDG and CHEF, which are folded so that strand B is opposite strand C, I opposite H, and so on.(source wikipedia).
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The birnavirus crystal structure reveals structural relationships among icosahedral viruses
Fasseli Coulibaly , Christophe Chevalier, Irina Gutsche, Joan Pous, Jorge Navaza, St?phane Bressanelli, Bernard Delmas, F?lix A Rey
Cell. 2005 Mar 25;120(6):761-72.