Crystallization strategies for and structural analyses of all of the players in the faRel2/aTfaRel2 toxin–antitoxin system are reported.

A putative exopolyphosphatase (PPX) from Z. mobilis (ZmPPX) was expressed, purified and crystallized. PPX enzymes regulate intracellular inorganic polyphosphate levels in microbial cells in response to external stresses. N-terminal truncation of ZmPPX based on primary-sequence analysis resulted in an improvement in diffraction from 3.3 to 1.8 Å resolution.

A putative ApaG gene product from X. campestris pv. campestris was overexpressed in E. coli, purified and crystallized. The crystals diffracted to a resolution of at least 2.3 Å.