Dynamics and interactions of ADP/ATP transporter AAC3 in DPC detergent are not functionally relevant

A recent study (S. Bruschweiler et al and J.J. Chou, Nat. Struct. Mol. Biol. 2015) used solution-state NMR spectroscopy to examine the interactions and dynamics of the yeast mitochondrial inner-membrane ADP/ATP carrier, yAAC3. The authors present NMR based interaction studies and millisecond dynamics. Their main conclusion is that yAAC3 in dodecylphosphocholine detergent micelles is functional and undergoes functionally relevant motions that depend on substrate and inhibitor. We contradict these results and show that the protein sample is partially misfolded; the dynamics are not correctly fitted and do not appear to be dependent on substrate/inhibitor. Together, our findings suggest that yAAC3 in DPC detergent is misfolded.