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1929: Two-sided Interface Design

Closed since almost 2 years ago

Intermediate Overall Design


December 11, 2020
Max points

Design an interface between two protein chains! This is a followup puzzle to Puzzle 1903b, with a greater allowance of insertable residues and a stricter Core Existence Objective. The starting structure includes two helical hairpins that are frozen in place and separated from one another. We want to build on these hairpins to create a binding interface between the two protein chains. However, the starting position of the hairpins is important, so the locked hairpins are held in place by strong constraints. The only way to make the two chains bind will be to fold up a brand new interface between them.

As you build on the two hairpins, it will be important to make a strong core with each chain, so that the chains fold up correctly. It will also be important to have a strong core at the interface where the two chains come together, so that they bind each other tightly. Keep an eye on the Core Existence Objective, which tracks all of these core residues together. Players may add up to 40 additional residues at a cost of 55 points per residue. See the puzzle comments for Objective details.

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bkoep Staff Lv 1

Core Existence: Total (max +5000)
Ensures that at least 32% of residues are buried in the core of the entire solution.

Residue Count (max +2200)
Penalizes added residues at a cost of 55 pts per residue. Players may add up to 40 residues, for a total of 220.

Buried Unsats (max +500)
Penalizes polar atoms that cannot make hydrogen bonds, -150 points per atom (not including symmetric copies).

Interaction Energy (max +500)
Monitors that all large PHE, TYR, and TRP residues are scoring well.

SS Design (max +500)
Penalizes all CYS residues. Penalizes GLY, ALA residues in sheets. Penalizes GLY, SER, THR in helices.

Ideal Loops (max +500)
Penalizes any loop region that does not match one of the Building Blocks in the Blueprint tool. Use "Auto Structures" to see which regions of your protein count as loops.

LociOiling Lv 1

Just like puzzle 1903b, this puzzle features a non-ideal loop than can't be fixed. It's between segments 90 and 91 at the start of the puzzle. The segment numbers can change if you add or delete segments.

As Boots pointed out last time, the two segments aren't even part of the same chain, and there's no way to change that. It's not clear why the ideal loops filter thinks they could be a single section of loop. It's one of those Foldit things, but everyone will lose the same 100 bonus points, so it's a level playing field.