Interacting selectively and non-covalently with a sequence of DNA that is a bacterial-type enhancer region in order to activate transcription by bacterial-type RNA polymerase. The transcription factor may or may not also interact selectively with a protein or macromolecular complex. Enhancers for sigma-54 holoenzymes are typically located 80 to 150 base pairs upstream from the transcription start site. Some transcription units dependent on sigma-70 holoenzymes may also include enhancer sequences.