Side-by-side comparison of the TrV and CrPV capsid proteins. CrPV VP1, VP2 and VP3 were superposed on the jelly rolls of their TrV counterparts and are shown side by side in two orthogonal views. Note the striking similarity of the path of the N-tails, despite an amino-acid sequence conservation of only about 20%. The CHEF and BIDG β-sheets of the jelly rolls are coloured red and yellow, respectively (note the way that the two β-sheets alternate about the fivefold and quasi-sixfold axes of the particles in the bottom row). VP1 segments involved in the projections by the fivefold axes are shown in blue and those from VP3 are shown in cyan. These features are coloured identically in the structural alignment (Fig. 5). Note that the exposed surface features are quite different in the two viruses despite the remarkable structural conservation of the capsid framework.