Presents a coherent account of many productive lines of investigation, organized as a series of mini-reviews that focus on major research areas including studies on the structure and mechanisms of action of bacterial, viral, and eukaryotic RNA polymerases, and the transcription factors that control their activities. Each review provides a brief but up-to-date account of the progress of research in a particular area, a discussion of the major issues and questions driving that research, and a brief description of the evolving approaches and technologies used to address those questions. Annotation copyright by Book News, Inc., Portland, OR