Figure 3

Polymorphic residues within known P. falciparum structures are predominantly surface exposed. Relative solvent accessibility (RSA) is shown for residues with and without identified polymorphisms. RSA represents the proportional surface area of a residue that is exposed to solvent, relative to the maximum possible exposure for that amino acid. RSA was calculated using the maximum accessible surface area (ASA) values from Rost & Sanders³⁶. Box-and-whisker plots show median (red line) and interquartile range (box) of residue RSA values for each group. Violin plots show the smoothed distribution of RSA values for each group (violin plots employ a Kernel Density Estimation to compute an empirical probability distribution for each group). Polymorphic residues shown are both those with underlying non-synonymous SNPs regardless of allele frequency (n = 204), and those with underlying non-synonymous SNP with a minor allele frequency (MAF) ≥ 5% (n = 105). The majority of residues in the dataset did not have underlying polymorphisms (n = 28,869). Sequence polymorphisms were obtained from 65 Gambian isolates from Amambua-Ngwa et al.²⁴, accessed via PlasmoDB. Polymorphic residues had significantly higher RSA values than the background RSA levels (p < 0.0001, Mann-Whitney U test), and polymorphic residues with a MAF ≥ 5% had significantly higher RSA than all polymorphic residues (p = 0.04, Mann-Whitney test).