As a test case for our newly designed fragment library, we performed a crystallographic fragment screening with the antibacterial drug target TrxR from M. smegmatis. With this protein, a hit rate of 44% was achieved for the F2X entry library. Here, for each fragment, two Msm-TrxR crystals were soaked for 3 hours, flash-frozen and a data set collected at BL14.2 of HZB. The refined data sets obtained from the auto-processing pipelines were screened for bound ligands using LigandFit. 24 fragments have been found to bind at eight different sites on the Msm-TrxR (Figure ). Seven of these fragments are located on the surface (shown in green) and might not influence the function of the enzyme. The remaining 17 fragments are located either in the dimer interaction site (purple), the Trx-binding site (orange) or the NADPH-binding site (cyan).