Characterization of a Small Ribozyme with Self-Splicing Activity

Bibliographic Details
Main Author: Harris, Lorena Beatriz
Language:English
Published: Bowling Green State University / OhioLINK 2008
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1225668492
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-bgsu12256684922021-08-03T05:28:38Z Characterization of a Small Ribozyme with Self-Splicing Activity Harris, Lorena Beatriz Molecular Biology Ribozymes pathogen self-splicing fungi Introns are common in the rRNA gene loci of fungal genomes, but biochemical studies to investigate splicing are rare. Here, self-splicing of a very small (67 nucleotide) group I intron is demonstrated. The PaSSU intron (located within the rRNA small subunit gene of Phialophora americana) splices in vitro under group I intron conditions. Most group I ribozymes contain pairing regions P1 - P10, with a conserved G•U pair at the 5' splice site, and a G at the 3' intron border. The PaSSU intron contains only P1, P7, and P10. While it contains the G•U pair at the 5' splice, a U is found at the 3' end of the intron instead of a G. Phylogenetic analysis places it within subgroup IC1, whose members are found in the nuclear rRNA genes of fungi. The structural elements are similar to those in the centermost regions of other group I introns. Its size can be explained by a single large deletion that removed P2 through much of P9. Part of the original P9region has assumed the function of P7. Its small size and genealogy makes it an excellent model to study RNA catalysis and evolution. Site-specific mutations have confirmed the essential character of 15% of the nucleotides that conform the intron. From the mutation done until today, around a third part of the intron may not be essential to achieve splicing characteristics. Ten nucleotides were mutated and inhibit intron removal. However, some induce alternative splicing. Nucleotidesfound in 5' exon-intron border, at P1, P7 and P10 that played essential roles are here demonstrated.Also, comparison among different Phialophora isolates that contain natural mutations have been studied to understand the evolutionary pattern involved in the gain, maintenance and loss of this intron in this species. 2008-12-03 English text Bowling Green State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1225668492 http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1225668492 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Molecular Biology
Ribozymes
pathogen
self-splicing
fungi
spellingShingle Molecular Biology
Ribozymes
pathogen
self-splicing
fungi
Harris, Lorena Beatriz
Characterization of a Small Ribozyme with Self-Splicing Activity
author Harris, Lorena Beatriz
author_facet Harris, Lorena Beatriz
author_sort Harris, Lorena Beatriz
title Characterization of a Small Ribozyme with Self-Splicing Activity
title_short Characterization of a Small Ribozyme with Self-Splicing Activity
title_full Characterization of a Small Ribozyme with Self-Splicing Activity
title_fullStr Characterization of a Small Ribozyme with Self-Splicing Activity
title_full_unstemmed Characterization of a Small Ribozyme with Self-Splicing Activity
title_sort characterization of a small ribozyme with self-splicing activity
publisher Bowling Green State University / OhioLINK
publishDate 2008
url http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1225668492
work_keys_str_mv AT harrislorenabeatriz characterizationofasmallribozymewithselfsplicingactivity
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