Foldit Puzzles

2005b: IL-2R Binder Design: Round 1

Note: This puzzle replaces the original Puzzle 2005 which used a mis-calibrated score function. Players may load in solutions from the original Puzzle 2005.

2004: Revisiting Puzzle 67: Integrase

This is a throwback puzzle to the early days of Foldit. This DNA-binding domain is part of a bacterial integrase protein, which facilitates the insertion of new DNA into the bacterial chromosome. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been.

2003: Symmetric D2 Tetramer Design: Limited Interface

Design a D2 symmetric protein tetramer, with 4 identical chains of 90 residues each! Unlike the cyclical C4 symmetry that we are used to, the proteins in this puzzle will come together as a "dimer of dimers" with D2 symmetry. This puzzle has no H-Bond Network Objective, but there is "Core Limit: Complex" objective meant to regulate the size of the interface between symmetric chains. An interface that is too large, with too many orange hydrophobics, can prevent the individual subunits from folding properly; on the other hand, an interface that is too small does not provide enough interactions for assembly The "Core Limit: Complex" objective will incur penalties if there are too many, or too few buried residues in the total assembly. This puzzle uses the Buried Unsats Objective, with a large penalty for buried polar atoms that can't make H-bonds. See the puzzle comments for more Objective details.

2002: TGF Receptor Binder Design: Round 5

Design a protein that can bind to the TGF-beta receptor! We have been seeing excellent designs from the previous puzzles, so this puzzle is set up just the same. Try to max out the Contact Surface Objective by using sidechains that pack closely against the target binding site!

2001: Revisiting Puzzle 66: Cytochrome

This is a throwback puzzle to the early days of Foldit. This protein helps to transfer electrons between substrates in bacteria. The protein is modeled here in reducing conditions, and no disulfides are expected to form. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been.

2000: Symmetric D2 Tetramer Design: Limited Interface

Design a D2 symmetric protein tetramer, with 4 identical chains of 70 residues each! Unlike the cyclical C4 symmetry that we are used to, the proteins in this puzzle will come together as a "dimer of dimers" with D2 symmetry. This puzzle has no H-Bond Network Objective, but there is "Core Limit: Complex" objective meant to regulate the size of the interface between symmetric chains. An interface that is too large, with too many orange hydrophobics, can prevent the individual subunits from folding properly; on the other hand, an interface that is too small does not provide enough interactions for assembly The "Core Limit: Complex" objective will incur penalties if there are too many, or too few buried residues in the total assembly. This puzzle uses the Buried Unsats Objective, with a large penalty for buried polar atoms that can't make H-bonds. See the puzzle comments for more Objective details.

1999: Tie2 Binder Design: Round 4

Design a protein to bind to the Tie2 receptor! We saw lots of great designs in the previous Round 3 puzzle, so this puzzle is set up just the same. Try to max out the Contact Surface Objective by using sidechains that pack closely against the target binding site!

1996: Unsolved Astrovirus Capsid Multi-Start

Scientists at UC Santa Cruz need your help! They have been unable to solve the structure of the human astrovirus (HAstV) capsid protein, which is involved in host cell receptor binding. They have some experimental data about the protein structure, but have been unable to find a model that explains the experimental data. This is a multi-start puzzle, with 5 different starting structures provided by the Zhang structure prediction server. Reset the puzzle to cycle through the different starting models. We are giving you 2 weeks to try out all 5 starting models.

1998: Symmetric D2 Tetramer Design: Limited Interface

Design a D2 symmetric protein tetramer, with 4 identical chains of 80 residues each! Unlike the cyclical C4 symmetry that we are used to, the proteins in this puzzle will come together as a "dimer of dimers" with D2 symmetry. This puzzle has no H-Bond Network Objective, but there is "Core Limit: Complex" objective meant to limit the size of the interface between symmetric chains. An interface that is too large, with too many orange hydrophobics, can prevent the individual subunits from folding properly. The "Core Limit: Complex" objective will incur penalties if there are too many buried residues in the total assembly. This puzzle uses the Buried Unsats Objective, with a large penalty for buried polar atoms that can't make H-bonds. See the puzzle comments for more Objective details.

Design of the Month: May 2021

This sandbox puzzle features a symmetric tetramer design by ichwilldiesennamen from Puzzle 1977. An exceptional 100% satisfied H-bond network is buried at the interface with zero BUNS! That should prevent this design from forming aggregates or off-target assemblies. For more, check out Foldit Lab Report #19 on YouTube! This sandbox puzzle is non-competitive and will not award any points.