This is the C-terminal domain of AbrB protein from Bacillus subtilis. AbrB is a transition state regulator. Functions of AbrB include biofilm formation, antibiotic production, competence development, extracellular enzyme production, motility, and sporulation. The C-terminal domain is responsible for multimerization and, to a lesser extent than the N-terminal domain, also contributes in DNA binding [1].

1: Structure and DNA-binding traits of the transition state regulator AbrB. Olson AL, Tucker AT, Bobay BG, Soderblom EJ, Moseley MA, Thompson RJ, Cavanagh J; Structure. 2014;22:1650-1656. PMID:25308864