Use of reiterative selection for defining protein-nucleic acid interactions.

Nucleic acids not only code for proteins, but also play a role in a multitude of biological processes, where they act as structural supports, binding sites, co-factors, or catalysts. Recently, an array of techniques has been developed in which molecules that are best fit to perform a given task are selected from a pool of randomized RNA or DNA molecules. These techniques can provide information about the structure/function relationship governing the various biochemical properties of RNA and DNA, including their interaction with proteins. Immediate applications are found not only in the field of transcriptional regulation, but also in the field of RNA-based catalysis.