Correction to: Nature Communications https://doi.org/10.1038/s41467-017-01424-4, published online: 20 Jul 2017

The original version of this article contained an error in Fig. 5c. The label for the back series of columns was incorrectly given as ‘1.5 mM pH 2’, rather than the correct ‘1.5 mM pH 7’. This has now been corrected in both the PDF and HTML versions of the article.