- August 16, 2022
- Max points
Design a beta strand and a separate protein that can bind to it! This puzzle has added an H-bond Network Objective, to reward sidechain H-bonds between the binder and strand target. For maximum effect, the H-bond network should be buried away from solvent. Similar to Round 2, a Secondary Structure Objective will penalize designs with >50% helices. We think it will be important to design a binder that forms a strong beta sheet around the target strand.
This is a two-sided design problem, where we can design the sequence of both binding partners. The goal is to design a pair of proteins that will self-associate in solution. This is especially useful for bioengineering applications where we might want to use a short peptide as a "signal" that can be recognized by its binding partner. Although the short peptide may be flexible in solution, we would like to bind it in the shape of beta strand, so the target backbone has been frozen as a beta strand. However, you may still change the sidechains of the strand target to any amino acid you want!
AlphaFold predictions are enabled for the designed binder. Once you've designed a binder for the strand target, upload your solution for AlphaFold using the AlphaFold prediction tool. AlphaFold will predict the structure of your binder chain only (i.e. in the unbound state, in the absence of the strand target). If you load this prediction, then Foldit will attempt to align the prediction with your solution (i.e. in the bound state, making an interface with the strand target). If you continue working off of the AlphaFold prediction, you may need to make adjustments at the interface where the binder interacts with the target. See the puzzle comments for additional Objectives.