Correction to: Nature https://doi.org/10.1038/s41586-022-04402-z Published online 9 February 2022

In the version of this article initially published, the first sentence of the Author contributions section was truncated. The section has been amended to begin “V.B.K. performed protein purification, atomic model building and structural interpretation.” The error has been corrected in the HTML and PDF versions of the article.