title: Crystal structure of a luteoviral RNA pseudoknot and model for a minimal ribosomal frameshifting motif.
abstract: To understand the role of structural elements of RNA pseudoknots in controlling the extent of -1-type ribosomal frameshifting, we determined the crystal structure of a high-efficiency frameshifting mutant of the pseudoknot from potato leaf roll virus (PLRV). Correlations of the structure with available in vitro frameshifting data for PLRV pseudoknot mutants implicate sequence and length of a stem-loop linker as modulators of frameshifting efficiency. Although the sequences and overall structures of the RNA pseudoknots from PLRV and beet western yellow virus (BWYV) are similar, nucleotide deletions in the linker and adjacent minor groove loop abolish frameshifting only with the latter. Conversely, mutant PLRV pseudoknots with up to four nucleotides deleted in this region exhibit nearly wild-type frameshifting efficiencies. The crystal structure helps rationalize the different tolerances for deletions in the PLRV and BWYV RNAs, and we have used it to build a three-dimensional model of the PRLV pseudoknot with a four-nucleotide deletion. The resulting structure defines a minimal RNA pseudoknot motif composed of 22 nucleotides capable of stimulating -1-type ribosomal frameshifts.
authors.affiliation: Department of Biochemistry, Vanderbilt University, School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: Pradeep S
authors.initials: PS
authors.lastname: Pallan
authors.forename: William S
authors.initials: WS
authors.lastname: Marshall
authors.forename: Joel
authors.initials: J
authors.lastname: Harp
authors.forename: Frederic C
authors.initials: FC
authors.lastname: Jewett
authors.forename: Zdzislaw
authors.initials: Z
authors.lastname: Wawrzak
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Brown
authors.forename: Alexander
authors.initials: A
authors.lastname: Rich
authors.forename: Martin
authors.initials: M
authors.lastname: Egli
mesh_terms: D001483:Base Sequence; D018360:Crystallography, X-Ray; D018965:Frameshifting, Ribosomal / Q000235:genetics*; D017793:Luteovirus / Q000235:genetics*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics*; D011198:Solanum tuberosum / Q000821:virology; D013816:Thermodynamics
chemical_list: D012367:RNA, Viral