A. Hungler, A. Momin, K. Diederichs, S.T. Arold
Journal of Applied Crystallography, Volume 49, Part 6, pp. 2252-2258, (2016)
Solving the phase problem in
protein X-ray crystallography relies heavily on the identity of the
crystallized protein, especially when molecular replacement (MR) methods are
used. Yet, it is not uncommon that a contaminant crystallizes instead of the
protein of interest. Such contaminants may be proteins from the expression host
organism, protein fusion tags or proteins added during the purification steps.
Many contaminants co-purify easily, crystallize and give good diffraction data.
Identification of contaminant crystals may take time, since the presence of the
contaminant is unexpected and its identity unknown. A webserver (ContaMiner)
and a contaminant database (ContaBase) have been established, to allow fast
MR-based screening of crystallographic data against currently 62 known
contaminants. The web-based ContaMiner (available at http://strube.cbrc.kaust.edu.sa/contaminer/)
currently produces results in 5 min to 4 h. The program is also available in a
github repository and can be installed locally. ContaMiner enables screening of
novel crystals at synchrotron beamlines, and it would be valuable as a routine
safety check for ‘crystallization and preliminary X-ray analysis’ publications.
Thus, in addition to potentially saving X-ray crystallographers much time and
effort, ContaMiner might considerably lower the risk of publishing erroneous