Closed

This is a throwback puzzle to the early days of Foldit. In the struggle for limited resources, some strains of the bacteria E. coli produce a potent toxin to fight off competing strains. This small immunity protein protects the aggressor E. coli from falling victim to its own toxin. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been.

This symmetric design puzzle has C3 symmetry, with three symmetric chains. The H-bond Network Objective encourages players to bury H-bond Networks at the interface between the two chains. We've doubled the H-bond Network bonus, but we'd like players to focus on building networks deep in the core of the protein complex. There are a couple other bonuses in effect; see the puzzle comments for details. The Baker Lab will run folding predictions on your solutions for this puzzle, and those that perform well will be synthesized in the lab. Remember, you can use the Upload for Scientists button for up to 5 designs that you want us to look at, even if they are not the best-scoring solutions!

Note: This puzzle was posted erroneously with the wrong setup. The puzzle was closed early, and has been reposted with the correct setup as Puzzle 1615b.

This is a throwback puzzle to the early days of Foldit. This protein is found on the surface of bacteriophage fd, a virus that infects E. coli. It is responsible for penetrating the cell membrane of the host bacteria, allowing virus to enter the cell. This protein contains four cysteines that oxidize to form two disulfide bonds. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been.

This symmetric design puzzle has C2 symmetry, with two symmetric chains. The H-bond Network Objective encourages players to bury H-bond Networks at the interface between the two chains. We've doubled the H-bond Network bonus, but we'd like players to focus on building networks deep in the core of the protein complex. There are a couple other bonuses in effect; see the puzzle comments for details. The Baker Lab will run folding predictions on your solutions for this puzzle, and those that perform well will be synthesized in the lab. Remember, you can use the Upload for Scientists button for up to 5 designs that you want us to look at, even if they are not the best-scoring solutions!

The structure of this protein is still unknown. Secondary structure predictions (from PSIPRED) are marked on the starting structure, and provide clues about where the protein might form helices and sheets!

This is a throwback puzzle to the early days of Foldit. This small disulfide-rich protein is produced by the moth H. virescens as a defense against certain bacterial and fungal infections. This protein contains six cysteines that oxidize to form three disulfide bonds. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been.

This symmetric design puzzle has C2 symmetry, with two symmetric chains. The H-bond Network Objective encourages players to bury H-bond Networks at the interface between the two chains. We've doubled the H-bond Network bonus, but we'd like players to focus on building networks deep in the core of the protein complex. There are a couple other bonuses in effect; see the puzzle comments for details. The Baker Lab will run folding predictions on your solutions for this puzzle, and those that perform well will be synthesized in the lab. Remember, you can use the Upload for Scientists button for up to 5 designs that you want us to look at, even if they are not the best-scoring solutions!

Design a protein to stabilize the CR2-binding helices! Complement receptor 2 (CR2) is a protein found on the surface of human B-cells, which respond to viruses and other pathogens found in the body. When the CR2 protein is activated, these immune cells become especially sensitive. We want to design a protein that can bind to CR2 and help trigger a strong immune response. Such a protein could boost the effectiveness of vaccines. The starting structure contains two helices from a natural protein, which is known to bind CR2 but is not very stable. We're asking Foldit players to design a protein to stabilize these two helices in their starting orientation. The side chains involved in CR2 binding are frozen; Foldit players should avoid building around these residues, which need to remain accessible for CR2 binding. Some protein design Objectives are in effect; see the puzzle comments for details.

This symmetric design puzzle has C2 symmetry, with two symmetric chains. The H-bond Network Bonus encourages players to bury H-bond networks at the interface between the two chains. We've doubled the H-bond network bonus, but we'd like players to focus on building networks deep in the core of the protein complex. There are a couple other bonuses in effect; see the puzzle comments for details. The Baker Lab will run folding predictions on your solutions for this puzzle, and those that perform well will be synthesized in the lab. Remember, you can use the Upload for Scientists button for up to 5 designs that you want us to look at, even if they are not the best-scoring solutions!