Are all Histidines in Foldit the same?
|Opened on:||Tuesday, April 10, 2018 - 23:33|
|Last modified:||Friday, April 13, 2018 - 02:44|
In Puzzle 1500 (http://fold.it/portal/node/2004921),
"Aflatoxin Challenge: Round 6 with Insertions",
in a structure I called Je4 (made in a file I called 1500k9),
I mutated residues 42 43 52 & 74 to Histidine and then tried
to hydrogen bond their N-H groups to various O's on the
aflatoxin (residue 229). Oddly, the N-H groups on
His42 & His74 were atoms 10 & 17 while the N-H groups on
His43 & His52 were atoms 7 & 15. Is it normal in Foldit
puzzles to have different types of Histidines in the protein?
Do these reflect the N1-H or N3-H tautomers of Histidine as
described below? How many different types of Histidine does
Foldit use? From the following, it seems like there are
3 possible types (sometimes called HSD HSE & HSP):
If Foldit has more than one type of Histidine, does it let the
different types interconvert like it does with pairs of cysteines
that get close enough together to form disulfide bonds?