Tetrahymena Group I intron ribozyme

Use of FPA to Study Helical Dynamics in a Complex RNA, with the Tetrahymena Group I Intron Ribozyme as an Example... 

In studies of the reactions mediated by the ribozyme from the Tetrahymena group I intron, detailed kinetic and thermodynamic analysis, combined with modifications at the atomic level, helped to define the reaction mechanism of this ribozyme at the atomic level [27, 48, 123-128]. Modification at the atomic level has generally involved replacement by a sulfur atom of an... 

Golden, B. L., Podell, E. R., Gooding, A. R., and Cech, T. R. (1997). Crystals by design A strategy for crystallization of a ribozyme derived from the Tetrahymena group I intron. 

Specific metal ion binding sites are directly observed in the crystal structures of hammerhead ribozymes [18], P4—P6 domain of Tetrahymena group I intron [19], transfer (tRNA) [20], GAAA tetraloop receptor [21], sarcin-ricin loop [22], and MMTV pseudoknots [23], for example. High... 

Ribozymes Appeared. Tetrahymena thermophila revealed its group I intron ribozymes in Thomas Czeh s laboratory. Ribozymes catalyze their substrates ( like protein enzymes ) infra- and intermolecularly. The tetrahymena ribozyme s intramolecular catalysis consists of self-splicing (Golden BL et al Howard Hughes Medical Institute, Department of Chemistry and Biochemisby, University of Colorado, Boulder, CO. Science 1998 282 259-264). Alu ribonucleoproteins consists of polymerase Ill-transcribed Alu sequences and signal recognition proteins (SRP9/14) united. In the ribosome, these units inhibit IRES-mediated (internal ribosome enfry site) translation initiation (Ivanova E et al Nucleic Acids Res 2015 43 2874-2887). 

The Cech group described an X-ray crystallographic structure of the group I intron from Tetrahymem thermophila in a Science magazine research article published in 1998 (PDB IGRZ). The 5.0-A resolution crystal structure included 247 nucleotides comprising most of the Tetrahymena thermophila intron. At this resolution, clear density for the ribozyme backbone was seen, and stacked bases were visualized as continuous tubes of electron density. 

Fig. 2. The P4-P6-domain of the group I intron of Tetrahymena thermophila. A Schematic representation of the secondary structure of the whole self-cleaving intron (modified after Cate et al. [34]). The labels for the paired regions P4 to P6 are indicated. The grey shaded region indicate the phylogenetically conserved catalytic core. The portion of the ribozyme that was crystallized is framed. B Three dimensional structure of the P4-P6 domain. Helices of the PSabc extension are packed against helices of the conserved core due to a bend of approximately 150° at one end of the molecule...

Karbstein, K., Lee, J., and Herschlag, D. (2007). Probing the role of a secondary structure element at the 5 - and splice sites in group I intron self-splicing The Tetrahymena L-16ScaI ribozyme reveals a new role for the G U pair in self-splicing. Biochemistry 46, 4861-4875. 

Fig. 1A-F The two-dimensional structures of various ribozymes. The ribozyme or intron portion is printed in black. The substrate or exon portion is printed in gray. Arrows indicate sites of cleavage by ribozymes A (left) the two-dimensional structure of a hammerhead ribozyme and its substrate. Outlined letters are conserved bases that are involved in catalysis right) The y-shaped structure of the hammerhead ribozyme-sub-strate complex B-F the two-dimensional structures of a hairpin ribozyme, the genomic HDV ribozyme, a group I ribozyme from Tetrahymena, a group II ribozyme from S. cer-evisiae (aiy5), and the ribozyme of RNase P from E. coli...

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