Fig. 2: Sequence and structural arrangement of stabilising mutations designed in PV rsVLPs.

a Schematic display of stabilising mutations designed for each PV serotype with a description of their location relative to capsid features. Those mutations present in each serotype are denoted in bold. The four-digit sequence numbering denotes the mature capsid subunit in the first digit (e.g. R4018G refers to VP4 R18G). b Cartoon of an icosahedral PV capsid, with a single pentamer shaded in pale yellow. Five-fold, three-fold and two-fold symmetry axes are labelled with symbols. A single protomeric subunit within the pentamer is highlighted and subunits coloured blue (VP1), green (VP0) and red (VP3). The lipid bound in the VP1 hydrophobic pocket is depicted in black. Key capsid features from (a) are labelled and the canyon around the five-fold axis is shown as a semi-transparent grey ring. The expanded view shows the capsid protomer as a molecular cartoon with the positions of all stabilising mutations from (a) mapped onto the structure and colour-coded based on their insertion into the PV1-SC6b (blue), PV2-SC6b (green) and PV3-SC8 (red) rsVLPs. Mutations present in more than one rsVLP are coloured cyan. c The structures of serotypes PV1, PV2 and PV3 capsids (based on PDB codes 1HXS, 1EAH and 1PVC, respectively) are shown as surface representations shaded blue, green and red respectively with their antigenic sites coloured purple. Mutations introduced into the rsVLP are coloured yellow. Five-fold, three-fold and two-fold symmetry axes are labelled with symbols and an icosahedral asymmetric unit (AU) is highlighted with a white triangle. Enlarged views of each AU are presented beneath the corresponding capsids.