Bacterial Transcription Factors: Regulation by Pick “N” Mix

Transcription in most bacteria is tightly regulated in order to facilitate bacterial adaptation to different environments, and transcription factors play a key role in this. Here we give a brief overview of the essential features of bacterial transcription factors and how they affect transcript initiation at target promoters. We focus on complex promoters that are regulated by combinations of activators and repressors, combinations of repressors only, or combinations of activators. At some promoters, transcript initiation is regulated by nucleoid-associated proteins, which often work together with transcription factors. We argue that the distinction between nucleoid-associated proteins and transcription factors is blurred and that they likely share common origins. [Display omitted] •Bacterial transcription factor activity is modulated by environmental signals.•Most bacterial transcription factors bind at or near specific promoters and up- or down-regulate transcript initiation.•At many promoters, combinations of transcription factors work together to integrate different signals.•At many promoters, transcription factors work together with other DNA-binding proteins whose primary role is to sculpt the bacterial folded chromosome.