Bacterial chromatin is composed of the genetic material of the cell with its associated proteins and RNA molecules. The proteins provide structural and regulatory functions and frequently both functions can be found in individual polypeptides. Nucleoid-associated proteins form a very important group that combines genome architectural and gene regulatory functions. They are highly versatile and make important contributions to the control of transcription at a global level. In combination with DNA structural features such as supercoiling, nucleoid-associated proteins help to set the scene against which more focused aspects of gene control must operate. The combination of DNA structure, nucleoid-associated proteins and conventional transcription regulators provides the basis for an integrated gene control network in bacteria that is both environmentally responsive and highly adaptable.