Although identifiable using amino acid alignments [33] , the scope and impact of the many HRV A2 sequence deletions could not be fully qualified or quantified in this form. However, the inability to isolate the HRV A2 strains in vitro will hinder crystallography studies seeking to identify structural features, so we created structure-based alignments of the VP1-4 sequences from the prototype HRV A2 strain, HRV-QPM and used them to predict the presence of a-helices and b-sheets. These were identified in the eight, anti-parallel b-sheet 'jellyroll' conformation common among picornavirus proteins VP1, VP2 (including the EF 'puff') and VP3 [39] (Figure 2 ). Deletions in the VP1 protein imparted the most dramatic changes, reducing the protrusion of the BC, DE and HI loops compared with the other HRVs and introducing an additional C-terminal sheet-loop-sheet structure (arrow, Figure 2B ). Similar deletions were noted in all HRV A2 strains but only HRV-C026 was predicted to encode a similar, Cterminal structure in VP1. We next assembled the HRV-QPM structural proteins into a protomer by associating them with the closest sequence match (HRV-16) and then replicated this structure in silico into a viral pentamer. RMSD values were derived from the VP1, VP2 and VP3 structures of all HRVs with crystallography-derived data available (HRV-1A, -2, -3, -14 and -16) and compared to the predicted HRV-QPM structure. HRV-QPM and HRV-16 shared the highest conformational similarity (0.145, 0.142 and 0.147 Å for the VP1, VP2 and VP3 structures respectively), reflecting the use of HRV-16 in predicting the structure HRV-QPM. The poorest agreements were between HRV-1A and HRV-3 in VP1 (0.793 Å ) and VP3 (0.740 Å ) and between HRV-2 and HRV-14 in VP2 (0.697 Å ). At the ICAM-1 footprint, HRV-QPM values ranged from 0.064-0.106 Å and 0.709-0.779 Å in comparison to the same regions on HRV-16 and -14, respectively. Values could not be determined for HRV-2 because of the impact of deletions. We also examined the conformational agreement between an HEV footprint e.g. the CAR site employed by CV-B3, and the predicted HRV-QPM structure. A space filling model of the pentamer was next used to display SimPlot data in order to visualise regions of sequence conservation and diversification with a focus on the major (ICAM-1; Figure 3A ) and minor (VLDL-R; Figure 3C ) group domains. Overall, greater sequence identity was apparent between HRV-2 than HRV-14 reflecting the genomic similarity to HRV A strains, however within the domains defining HRV groups, HRV-QPM was most similar in its antigenic sites to the major group representative, HRV-14. Most sequence diversity was found in the VP2 protein while the most conserved protein in these comparisons was VP3.