Most transcription activator proteins have three important features that can be probed at the molecular level: they bind to specific sequences near promoters, they can be interconverted between active and inactive forms by covalent or noncovalent modification, and, when bound at target promoters, they can stimulate the initiation of transcription by RNA polymerase (1). This chapter is concerned with in vitro methods for measuring the transcription activation function of this important class of proteins. In most cases, these methods are applied to activators that have been substantially purified, and for which the target sequences are known and the binding sites characterized (other chapters in this volume cover methods for locating and investigating the binding sites for such activators). Here we are concerned with the measurement of the products of activation. Because Escherichia coli transcription activators have been studied more than any others, we will take these as the paradigm, though, in principle, the techniques can be applied to any organism for which in vitro systems have been developed.
|Title of host publication||Methods in Molecular Biology: Protein-DNA interaction protocols (ed. Tom Moss)|
|Number of pages||14|
|Publication status||Published - 1 Jan 2001|
|Name||Methods in Molecular Biology|