Written in English
|The Physical Object|
|Number of Pages||132|
Structural Insights Into Substrate Recognition by the Neurospora Varkud Satellite Ribozyme: Importance of U-Turns at the Kissing-Loop JunctionCited by: Ribozymes, or catalytic RNAs, were discovered a little more than 15 years ago. They are found in the organelles of plants and lower eukaryotes, in amphibians, in prokaryotes, in bacteriophages Author: Kyle Tanner. Introduction. Varkud Satellite (VS) RNA is an abundant, single-stranded, RNA that is found in the mitochondria of certain natural isolates of is transcribed by mitochondrial RNA polymerase from a double-stranded plasmid, VS DNA, and replicates by reverse transcription as a satellite of another plasmid (Kennell et al., ).VS RNA is capable of self-cleavage and self-ligation Cited by: The catalytic domain of VS RNA is converted into a trans-cleaving ribozyme by using a nucleotide fragment of the VS RNA from to (VS RNA numbering;). The minimal substrate consists of one nucleotide 5′ and 19 nucleotides 3′ to the cleavage site, and it Cited by:
The Neurospora VS ribozyme (Saville and Collins, ) can be used as a model system to show the usefulness of the algorithm in generating the functional fitness landscape of the molecule (Fig. ). When the ribosome reaches a stop codon in the mRNA, it has a release factor bind in the A site. The release factor hydrolyzes the bond between tRNA in the p site and the last amino acid of the polypeptide chain, freeing the polypeptide from the ribosome. In this study, we report on the structural and biochemical analyses of DSL. Structural analysis indicates that the active site, which consists of the selected sequence, attaches to the folded scaffold as designed. To see whether DSL resembles known Cited by: This ribozyme forms an amide linkage if the 5' OH of the ribozyme is replaced with a 5' NH 2, although the rate of bond formation is decreased about 3-fold by making the substitution ( vs. min-1 for ribozyme, vs. min-1 for the uncatalyzed reaction). 78 This ribozyme is the only one of the four that indisputably uses a Cited by: 4.
manner. The significance of different domains of the ribozyme structure and the importance of two tandem G:U wobble base pairs in the template domain were studied by kinetic characterization of mutant ribozymes. The wobble base pairs contribute to the catalytic rate enhancement, but . VS ribozyme undergo horizontal gene transfer with other Neuropora strains. VS ribozymes have nothing in common with other nucleolytic ribozymes. VS RNA has a unique primary, secondary, and tertiary structure. The secondary structure of the VS ribozyme consists of six helical domains (Figure). New catalytic structures from an existing ribozyme Edward A Curtis & David P Bartel Although protein enzymes with new catalytic activities can arise from existing scaffolds, less is known about the origin of ribozymes with new activities. Furthermore, mechanisms by which new macromolecular folds arise are not well characterized. A two-base ribozyme may catalyze the formation of 3′,5′ phosphodiester linkafold faster (Reader JS, Joyce GF Nature [Lond] ). Ribozymes commonly have an internal guide for substrate recognition near their 5′ terminus and a splice site (self-cleavage or catalytic site) where they cleave and splice the molecules.