I've followed with great attention the thread about 5ggn, and it
reminded me of a structure I solved eight years ago. It was actually
crystallized long before that, but the people working on the lab back
then failed to solve the structure due to the lack of a search model
for MR (there was no available homolog at the time) and also the fact
there were no softwares to detect twinning back then. Better armed
back in 2008, I managed to go on, found a solution using MOLREP with
2HYK (released a couple of years before) as a search model.
XTRIAGE detected pseudomerohedral twinning, and so I remember doing
everything I could to get that done right, including looking for
similar cases in the literature, and found out two articles (Declercq,
J. P. and Evrard, C. (2001) Acta Cryst., D57, 1829. and Rudolph, M.
G., Wingren, C., Crowley, M. P., Chien, Y.-H. and Wilson, I.A. (2004)
Acta Cryst., D60, 656.) on which the authors describes this case on
twinning in a monoclinic system when fortuitously the cell has
c*cos(beta)=-a/2.
So I proceeded with refinement, and the result is 3ILN, which we
finally published at J. Phys Chem B three years later (it also
included molecular dynamics simulation and discussion on
thermostability/thermophilicity). The current version at PDBREDO (
http://www.cmbi.ru.nl/pdb_redo/il/3iln/index.html ) made some
improvements to the structure we deposited back then, but I wonder if
there were any other serious error that went unnoticed, because it
does have a pretty crappy clashscore. Could a similar (I hope not as
serious) error have been done in that structure?
|