title: Crystallization of the 10-23 DNA enzyme using a combinatorial screen of paired oligonucleotides.
abstract: One of the most difficult steps in the X-ray crystallography of nucleic acids is obtaining crystals that diffract to high resolution. The choice of the nucleotide sequence has proven to be more important in producing high-quality crystals than the composition of the crystallization solution. This manuscript describes a systematic procedure for identifying the optimal sizes of a multi-stranded nucleic acid complex which provide high-quality crystals. This approach was used to crystallize the in vitro evolved 10-23 DNA enzyme complexed with its RNA substrate. In less than two months, 81 different enzyme-substrate complexes were generated by combinatorial mixing and annealing of complementary oligonucleotides which differed in length, resulting in duplexes of varying length, with or without nucleotide overhangs. Each of these complexes was screened against a standard set of 48 crystallization conditions and evaluated for crystal formation. The screen resulted in over 40 crystal forms, the best of which diffracted to 2.8 A resolution when exposed to a synchrotron X-ray source.
authors.affiliation: Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: J
authors.initials: J
authors.lastname: Nowakowski
authors.forename: P J
authors.initials: PJ
authors.lastname: Shim
authors.forename: G F
authors.initials: GF
authors.lastname: Joyce
authors.forename: C D
authors.initials: CD
authors.lastname: Stout
mesh_terms: D020650:Combinatorial Chemistry Techniques; D003460:Crystallization; D004247:DNA / Q000737:chemistry; D009690:Nucleic Acid Conformation; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry*; D012313:RNA / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D009692:Nucleic Acid Heteroduplexes; D012313:RNA; D004247:DNA