Puzzle 445 is broken
|Opened on:||Monday, August 8, 2011 - 03:54|
|Last modified:||Wednesday, August 10, 2011 - 23:03|
There are four major issues associated with the recently released puzzle 445:
1: Malformed Asparagine-- Asp 37 has the carboxyl end of the sidechain pointed at an extremely small angle to the base end. the amine end of the sidechain is affected, though by a lot less. See an image here:
http://fold.it/portal/files/chatimg/irc_99169_1312771984.png (credits to Enzyme for finding this)
2: This problem has to do with the amino acids 111 and 112. The problem is that the segment has a perpetually low backbone score, which is not solved by a rebuild of those and adjoining segments. In a related issue, the local wiggle function behaves erratically on those segments. Local wiggle moves the segments drastically, causing a dramatic score drop. This score drop is much greater than those sometimes seen on other puzzles. (credits auntdeen and myself)
3: The puzzle also has a very erratic opening. Shaking and wiggling the protein sometimes results in scores below zero, yet sometimes above 10000. Other results include 9680, 9740, and 9853. (auntdeen)
4: Finally, the puzzle also has threading problems. When threading model B onto model A, the protein has a extremely low score, and when shaken and wiggled out, extremely low backbone scores all over the protein. an image of this phenomenon: http://fold.it/portal/files/chatimg/irc_92665_1312773923.png (infajmc)
So far as we know, the bugs only appear on model B for 445.
Due to these errors, we recommend that you fix and re-release the puzzle.