Structural Analysis based on examples

1) CTF19:MCM21 interface .

▻ From previous exhibit (👈Click it!), it is known that hydrogen bonds and salt bridges in CTF19:MCM21 interface are highly conserved which contribute to high binding affinity while Van der Waals interactions only contribute in a large quantity.

▻ CTF19:MCM21 motif was firstly identified as one complex and co-expressed in COMA assembly in previous studies. It functions as a branch for the assembly of related inner kinetochore subunits and is essential for accurate chromosome segregagion¹.The high binding affinity between CTF19:MCM21 ensures its normal biological function.

Binding affinity and number of interactions of CTF19:MCM21 interface

Comparison of residue conservation and hydrophobicity for the CTF19:MCM21 binding interface

2) CTF19:CTF3 interface .

▻ CTF19:CTF3 complex shows low binding affinity without any hydrogen bond or salt bridge.

▻ Most of the residues involved in Van der Waals interactions have a low conservation degree (for more information click👉previous exihibit), indicating that merely forming Van Der Waals interactions is not enough to generate strong protein-protein binding.

Binding affinity and number of interactions of CTF19:CTF3 interface

Comparison of residue conservation and hydrophobicity for the CTF19:CTF3 binding interface

Reference

1.        Schmitzberger F, Richter MM, Gordiyenko Y, Robinson C V, Dadlez M, Westermann S.  Molecular basis for inner kinetochore configuration through RWD domain–peptide interactions . EMBO J. 2017;36(23):3458-3482. doi:10.15252/embj.201796636