Correction to: Nature Communications; https://doi.org/10.1038/s41467-017-01713-y, published online 23 Nov 2017.

The original version of this Article contained an error in Fig. 1. In panel d, the model on the right of the panel was incorrectly labeled ‘+Heme’, and should have read ‘− Heme’. This has now been corrected in both the PDF and HTML versions of the Article.