Nature Reviews Microbiology (2019) https://doi.org/10.1038/s41579-019-0159-8 Published online 5 March 2019

In Figure 3 of the article, the structures of the ring-opened β-lactam molecules were incorrect. This has now been corrected in the PDF and online. The authors apologize for any confusion caused.

Fig. 3
figure 3

Original and Corrected.