Fritz Eckstein & David M.J. Lilley 
Mechanisms of Transcription [PDF ebook] 

Mechanisms of Transcription presents a unique perspective on the fundamental processes of transcription. A collection of distinguished authors draws together the underlying mechanisms involved in the process of transcription. This includes RNA polymerase function and its interaction with promoter sequences, and the structures of the various components on the transcriptional machinery. Both prokaryotic and eukaryotic systems, NMR and crystallographic structures of a number of important eukaryotic transcription factors are discussed, as well as the role of chromatin structure.