title: In vitro selection methodologies to probe RNA function and structure.
abstract: In vitro selection, or SELEX, has been used both to characterize the interaction of natural nucleic acids with proteins and to generate novel nucleic acid-binding species, or aptamers. Although numerous reports have demonstrated the power of the technique, they have not expanded on the methodologies that can be used for selection. This review focuses on the considerations and problems involved in selecting protein-binding aptamers from a random-sequence RNA pool. As an illustration, we describe two approaches to selecting aptamers to a particular target, the HTLV-I Rex protein. In the first, complete randomization is used to find an artificial, high-affinity RNA binding site. In the second, the contributions of individual nucleotides and/or base pairs to the natural Rex-binding element are determined by mutating the wild-type sequence and selecting active binding variants.
authors.affiliation: Department of Chemistry, Indiana University, Bloomington 47405, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Conrad
authors.forename: S
authors.initials: S
authors.lastname: Baskerville
authors.forename: A D
authors.initials: AD
authors.lastname: Ellington
mesh_terms: D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D019020:Directed Molecular Evolution / Q000379:methods*; D016370:Gene Products, rex / Q000378:metabolism; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D016370:Gene Products, rex; D012313:RNA