Shape may affect the number of hydrophobic and hydrophilic residues at the interfaces
The number of hydrophobic and hydrophilic residues varies between interfaces, although more hydrophilic residues can be found in general.
Interestingly, grooved interfaces IML3:CHL4 (L:N) and CHL4:MCM21 (N:O) have similar hydrophobic:hydrophilic residues ratios (around 1:1). While the convex:concave shaped CHL4:CTF19 (N:P) accommodates much more hydrophilic residues (ratio of 1:1.28).
The residues involved in interface MCM16 : CHL4 (H:N) are too few to draw conclusions about flat interfaces.
Where are the Buried Solvent Assessible Areas (BSA)?
Using scraped data from Ranganathan et al. (2015), the generated histogram shows a right-skew.
The BSAs for major interfaces L:N (IML3:CHL4) and N:P (CHL4:CTF19) fall just at the right of the peak, whilst the BSA for interface N:O (CHL4:MCM21) is a column further from the peak. This suggests that the sizes of interfaces L:N (IML3:CHL4) and N:P (CHL4:CTF19) are much more common in protein-protein interactions, than that of interface N:O (CHL4:MCM21).
On the other hand, interface H:N (MCM16 : CHL4) falls to the furthest left of the skew. This indicates a small BSA and an unlikely one in terms of frequency.