Represses the expression of both the krueppel and knirps segmentation gap genes. Binds, in vitro, to the krueppel regulatory elements CD1 and CD2. It is required in the early embryo for the development of portions of the head and abdomen. Homodimer or heterodimer. Phosphorylated at multiple sites. Belongs to the bZIP family. It is uncertain whether Met-1, Met-3, Met-8 or Met-23 is the initiator.