missing disulphide bond in Turkey puzzle

Case number:845799-989003
Opened by:prot-bustr
Opened on:Tuesday, December 14, 2010 - 16:52
Last modified:Tuesday, August 23, 2011 - 19:54

From the guide it looks as if there should be a 4th disulphide bond between the cysteines at segments #6 and #127. But it isn't present at the start of the puzzle like the other three bonds. I have been unable to coax this bond to form by folding, and I suspect that it can't be done and the disulphide bonds need to be present at the start of the puzzle. I also suspect that a really good guide match won't be possible since the absence of this bond throws out the forces. Is this an oversight in the puzzle presentation, or is it to do with the unfolded state? I checked and #6 and #127 are some way apart in the partly unfolded starting position, and you wouldn't be able to get the bond in place at that time, so maybe that was the problem: could only set up three of the bonds at the start. Would like to know what the status of disulphide bonds is. It would be nice in future if we had some way of setting up a disulphide bond once we have the cysteines in the right alignment, but I can understand if that is too difficult to program correctly in FoldIt. I put a lot of effort into this puzzle and got the alignment of the other three bonding cysteine pairs pretty well, so it is unfortunate that I may not be able to complete the quartet!

(Tue, 12/14/2010 - 16:52  |  2 comments)

beta_helix's picture
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Joined: 05/09/2008
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"I suspect that it can't be done and the disulphide bonds need to be present at the start of the puzzle"

You are exactly right. Currently it is only possible to form disulphide bonds from the start or by explicitly telling Rosetta that residues X & Y should form a disulphide bond.

We are trying to come up with a way of doing this in Foldit, perhaps a button where you select 2 cysteine residues and click: "Form disulphide bond".

I'm sorry that you can't complete the quartet and we'll try to make sure beginner puzzles don't have unbonded disulphide bonds until we fix this problem.

Joined: 06/17/2010
Status: Open » Open

Puzzle need to be setted up for that kind of bonds.
Work in progress to make it automatic.


Developed by: UW Center for Game Science, UW Institute for Protein Design, Northeastern University, Vanderbilt University Meiler Lab, UC Davis
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