Ambiactive repressor and activator of the transcription of genes expressed during the transition state between vegetative growth and the onset of stationary phase and sporulation. It controls the expression of genes spovG and tycA. AbrB binds to the tycA promoter region at two A- and T-rich sites, it may be the sole repressor of tycA transcription. Interacts with BrxC. To B.subtilis Abh and SpoVT. It is uncertain whether Met-1 or Met-3 is the initiator. Truncated N-terminus. Truncated N-terminus.