Nat. Struct. Mol. Biol. 22, 647–648 (2015); published online 3 September 2015; corrected after print 12 October 2015.

In the version of this article initially published, the strapline mistakenly described a crystal structure of the Plasmodium falciparum enzyme. Plasmodium vivax is the correct species. The error has been corrected in the HTML and PDF versions of the article.