Correction to: Nature Chemical Biology https://doi.org/10.1038/s41589-018-0160-y, published online 3 December 2018

In the version of this article originally published, the present address for Petr Popov was incorrectly listed as ‘Koltech Institute of Science & Technology, Moscow, Russia’. The correct present address is ‘Skolkovo Institute of Science and Technology, Moscow, Russia’. The error has been corrected in the HTML and PDF versions of the paper.