Sequence identity comparison of CP subunits. The scores of the sequence identity matrices of the CP subunits were rounded and the percentage of sequences plotted against the sequence identity. The inlet contains box plots of the data for each CP subunit. 368 α-subunit and 299 β-subunit CP sequences were derived from CyMoBase[44, 45]. For calculating the sequence identities poorly aligned positions and divergent regions of the alignments were removed using Gblocks. Sequence identity matrices (2D-matrix tables containing sequence identities scores for each pair of sequences) were obtained by calculating the ratio of identities to the length of the longer of the two sequences after positions where both sequences contain a gap were removed.