The interfacial active site of the type IB GTP cyclohydrolase from Neisseria gonorrhoeae (grey and green ribbons), in complex with zinc (magenta ball) and the reaction intermediate analog and potent inhibitor 8-oxo-GTP (stick model). The structure sheds light on the complex and unique catalytic strategy of this potential antibacterial target, and offers a starting point for the design of specific inhibitors against the enzyme. For more information, please see study by Paranagama et al. in this issue, pages 1017–1039. Image provided by Manal Swairjo.