PIZSA is a knowledge-based statistical potential that evaluates protein-protein complexes based on interface residue pairing preferences and atomic propensities. Interacting residues are identified by a distance threshold and every interaction is assigned a score calculated from contributions of three different modes of interaction (main chain - main chain, main chain - side chain and side chain - side chain). Our method assigns a Z Score to protein complexes that estimates the likelihood of forming stable associations.

Users can either enter a PDB code or upload the three-dimensional structure of a protein complex for evaluation. Evaluation results are presented in a user-friendly format that summarises the overall complex scores and a break up of individual interacting residue scores. Users can also perform in silico mutational analysis that provides a difference in interaction score upon mutation to another amino acid. Our web server provides a platform for testing custom scoring potentials for residue pairing preferences as well as atomic propensities.

Quick links:

A pictorial description of the PIZSA algorithm.

Example of input and output pages for dimeric or multimeric protein complexes.

Dhawanjewar, A.S., Roy, A.A. and Madhusudhan, M.S., 2019. A knowledge-based scoring function to assess the stability of quaternary protein assemblies. bioRxiv, p.562520. [doi: https://doi.org/10.1101/562520].