Abstract
In this issue of Cell Chemical Biology, Ortega et al. (2016) present a study utilizing a click-chemistry-enabled fluorophosphonate for activity-based identification of serine hydrolases, pinpointing a range of proteins including previously annotated hypotheticals. The application of this technology on both actively replicating and non-replicating Mycobacterium tuberculosis gives us a glimpse of its serine hydrolytic landscape during different stages of metabolic activity.