This work focuses on a particular difficulty that may occur as a result of using kit-type systems for heterologous overexpression and purification of recombinant proteins, as well as purification of proteins from their natural sources—the accidental purification or contamination of the sample with a protein different than the protein of interest. In many cases, if the purified sample is used for crystallization, this error may not be detected until structures are determined. In this work, we present examples where the incorrect protein species were purified and/or crystallized, and describe procedures to quickly rule out the possibility that the crystals obtained in crystallization experiments are the effect of purification artifacts, should diffraction data be collected.
On this webpage we would like to present data for a quick reference. We also maintain a list of the PDB codes that can be used to identify common purification and crystallization artifacts.
If you would like to add a new purification or crystallization artifact to this list, please contact us and include a sequence or UniProt ID.