Crystallization of two operator complexes from the Vibrio cholerae HigBA2 toxin–antitoxin module

The HigA2 antitoxin and the HigBA2 toxin–antitoxin complex from Vibrio cholerae were crystallized in complex with their operator box. Screening of 22 different DNA duplexes led to two crystal forms of HigA2 complexes and one crystal form of a HigBA2 complex. Crystals of HigA2 in complex with a 17 bp DNA duplex belong to space group P3₂21, with unit-cell parameters a = b = 94.0, c = 123.7 Å, and diffract to 2.3 Å resolution. The second form corresponding to HigA2 in complex with a 19 bp duplex belong to space group P4₃2₁2 and only diffract to 3.45 Å resolution. Crystals of the HigBA2 toxin–antitoxin were obtained in complex with a 31 bp duplex and belonged to space group P4₁2₁2, with unit-cell parameters a = b = 113.6, c = 121.1 Å. They diffract to 3.3 Å resolution.