Self-splicing nucleic acids

Cech, T. R. (1990). Self-splicing of group I introns. Annu. Rev. Biochem. 59, 543—568. Cohen, S. B., and Cech, T. R. (2001). Engineering disulfide cross-links in RNA using thiol-disulfide interchange chemistry. Cun. Protoc. Nucleic Acid Chem. Chapter 5, Unit 5 1. 

Finally, novel nucleic acid catalysts have also been selected from random sequence pools (reviewed in Ref. 19). Joyce and co-workers have manipulated the function of the Group I self-splicing ribozyme, selecting variants that can utilize calcium or cleave DNA from partially randomized pools [20,21], Lorsch and Szostak [22] selected a polynucleotide kinase ribozyme from a completely random sequence pool that flanked a previously selected ATP binding site. Many of the novel ribozymes can catalyze reactions that are relevant to protein biosynthesis, bolstering arguments that translation may have arisen in a putative RNA world. For example, Lohse and Szostak [23] have selected ribozymes that can carry out an acyl transfer reaction, while Illangasekare et al. [24] have isolated a... 

First, given the wide range of prebiotic nucleic acids, ribose-based polymers may be the most eminently suited for catalysis. Eschenmoser has pointed out, for example, that nucleic acids constructed from hexose nucleotides form inflexible ribbon structures,61 poorly suited for convoluting into the complex shapes that are required for catalysis (e.g., the backbone of the projected tertiary structure of the Tetrahymena self-splicing intron folds back on itself a number of times).62 Conversely, backbones composed of acyclic nucleotides may be too flexible to adopt stable secondary structures (since a great deal of entropy would necessarily be lost on freezing into a given conformer). Ribose, on the other hand, has a limited flexibility because of its pseudorotation cycle, and RNA can adopt a variety of helical conformations. 

Some nucleic acids are capable of self-splicing. These catalytic DNA and RNA are known as deoxyribozymes (Li and Breaker, 1999 Sheppard et al, 2000) and ribozymes (Doherty and Doudna, 2000 Scott and Klug, 1996) respectively. The 3 - and/or 2 -hydroxyls of DNA/RNA serve as a catalytic site that invariably requires a metal ion for the catalytic activity. Deoxyribozymes are quasi-catalytic while ribozymes can be catalytic, e.g. ribonuclease P (RNase P) as well as quasi-catalytic, e.g. introns and hammerhead RNAs. RNase P resources are maintained at http //www.mbio.ncsu.edu/RnaseP/homeJitml... 

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). 

RNA (riboryme) showed enzymatic activity for transphosphorylation or hydrolysis of natural nucleic acids [82-85]. In the self-splicing of r- or m-RNA precursors the cleavage and ligation of the strands occurred to remove the... 

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