Correction to: Nature https://doi.org/10.1038/s41586-021-03673-2 Published online 3 June 2021

In the version of the article initially published, in Extended Data Fig. 5b, the “K444R” image was a duplicate of the “K444R+E484A” image due to an error in figure assembly. Extended Data Fig. 5 has now been updated with the correct “K444R” image in the HTML and PDF versions of the article.