Interacting selectively and non-covalently with a specific bacterial-type transcription regulatory DNA sequence and interacting selectively and non-covalently with copper(I) (Cu+) ion(s) and responding, e.g. by conformational change, to changes in the cellular level of copper(I) (Cu+), in such a way that copper ion binding regulates the activity of the transcription factor in order to stop, prevent, or reduce the frequency, rate or extent of cellular DNA-dependent transcription by a bacterial-type RNA polymerase.