Withdrawal: Human calpain-3 and its structural plasticity: Dissociation of a homohexamer into dimers on binding titin

The authors have withdrawn this article. The authors determined that the multimer that was purified and partially characterized by cryo-electron microscopy was not recombinant human calpain-3, but instead an E. coli protein contaminant, the bifunctional polymyxin resistance protein ArnA. This enzyme has internal histidine residues that likely enabled it to accumulate during Ni-Agarose affinity chromatography. To confirm this result, mass spectrometry sequencing was applied to the cryo-EM sample in question, which was found to be almost entirely ArnA.