DNA-Protein interactions, In: Encyclopedia of molecular cell biology and molecular medicine.

摘要

Proteins interact with DNA to form nucleoprotein complexes that mediate a host of important cellular processes. Nucleoprotein complexes are at the heart of many processes that include DNA recombination and repair, gene transcription, pathology, viral infection, and in defining DNA accessibility through chromosome structure. The interplay between proteins and DNA is dynamic and must be understood in a time-resolved fashion. Whilst a structural analysis of the individual components of such active complexes is essential, it has to be interpreted within the changing environment of a cell as it responds to alterations in the environment or as it transits through a preprogrammed cycle of growth, differentiation, and finally but not always, apoptosis. While the number of processes involving nucleoprotein complexes is large, and the mechanisms by which they carry out these functions are many and complex, there is, however, a restricted known set of the structure–function relationships involved. In this chapter, we will attempt to sketch out some of the more common of these, always relating this to possible dynamic changes that occur during the establishment of the nucleoprotein complex or take place during its function. We will pay particular attention to complexes involved in gene regulation at the level of DNA organization and at the level of the control of transcription where the information contained in the genome is decoded to produce the RNA complement that constitutes the transcriptome and hence, the potential proteome of a cell at any given moment. We have restricted our analysis to nucleoprotein complexes involved in processes in prokaryotic organisms for reasons of expediency, clarity, and because it falls within our own personal range of interest. However, the molecular basis for the formation of specific nucleoprotein complexes is clearly “system” independent and will be found across the whole range of living organisms; to paraphrase Jacques Monod “the same mechanisms present in E. coli will be at work in an elephant.” It's clearly logistically more favorable to study the former than the latter!