{"id":{"repo_id":"texas","oai_identifier":"oai:repositories.lib.utexas.edu:2152/807"},"canonical_url":"https://search.dev.ndltd.org/etd/texas/oai:repositories.lib.utexas.edu:2152/807","repository":{"repo_id":"texas","name":"University of Texas","base_url":"https://repositories.lib.utexas.edu/server/oai/request"},"display":{"title":"Interaction of the Neurospora crassa mitochondrial tyrosyl-tRNA synthetase with group I intron RNAs","abstract":"The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase, or CYT-18 protein, functions in splicing group I introns by promoting the formation of the catalytically active structure of the intron RNA. To investigate how CYT-18 stabilizes the active RNA structure, I used an Escherichia coli genetic assay with the phage T4 td intron to systematically test the ability of the CYT-18 protein to compensate for structural defects in the P7 region of the group I intron core. P7 is a long-range base-pairing interaction of the P3-P9 domain that forms the binding site for the splicing co-factor guanosine. My results show that CYT-18 can suppress numerous mutations that impair the self-splicing of the td intron, including mutations that disrupt base-pairing within the P7 region. CYT-18 suppressed mutations of phylogenetically conserved nucleotide residues at all positions tested, except for the universally conserved G-residue at the guanosine-binding site. Structure mapping experiments with some selected mutant introns showed that the P7 mutations impaired the formation of both P7 and P3, thereby grossly disrupting the P3-P9 domain. Previous work suggested that CYT-18 recognizes a conserved tRNA-like structure of the group I intron catalytic core. I used directed hydroxyl radical cleavage assays to show that the nucleotide-binding fold and C-terminal domains of CYT-18 interact with the expected group I intron cognates of the aminoacyl-acceptor stem and D-anticodon arms, respectively. Further, three-dimensional graphic modeling, supported by biochemical data, shows that conserved regions of group I introns can be superimposed over interacting regions of the tRNA in a Thermus thermophilus TyrRS/tRNATyr cocrystal structure.","abstract_html":"The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase, or CYT-18 protein, functions in splicing group I introns by promoting the formation of the catalytically active structure of the intron RNA. To investigate how CYT-18 stabilizes the active RNA structure, I used an Escherichia coli genetic assay with the phage T4 td intron to systematically test the ability of the CYT-18 protein to compensate for structural defects in the P7 region of the group I intron core. P7 is a long-range base-pairing interaction of the P3-P9 domain that forms the binding site for the splicing co-factor guanosine. My results show that CYT-18 can suppress numerous mutations that impair the self-splicing of the td intron, including mutations that disrupt base-pairing within the P7 region. CYT-18 suppressed mutations of phylogenetically conserved nucleotide residues at all positions tested, except for the universally conserved G-residue at the guanosine-binding site. Structure mapping experiments with some selected mutant introns showed that the P7 mutations impaired the formation of both P7 and P3, thereby grossly disrupting the P3-P9 domain. Previous work suggested that CYT-18 recognizes a conserved tRNA-like structure of the group I intron catalytic core. I used directed hydroxyl radical cleavage assays to show that the nucleotide-binding fold and C-terminal domains of CYT-18 interact with the expected group I intron cognates of the aminoacyl-acceptor stem and D-anticodon arms, respectively. Further, three-dimensional graphic modeling, supported by biochemical data, shows that conserved regions of group I introns can be superimposed over interacting regions of the tRNA in a Thermus thermophilus TyrRS/tRNATyr cocrystal structure.","abstract_has_math":false,"creators":["Myers, Christopher Allan"],"institution":"The University of Texas at Austin","degree_name":"Doctor of Philosophy","degree_level":"Doctoral","degree_discipline":"Ecology, Evolution, and Behavior","degree_department":null,"school":null,"contributors":[],"advisors":["Lambowitz, Alan"],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002","date_published":"2002","updated_at":"2026-07-24T05:01:00Z","subjects":[],"languages":["eng"],"rights":["Copyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["b57170137"],"render_values":[{"text":"b57170137","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2152/807","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Lambowitz, Alan"]},{"key":"dc:creator","label":"Author","values":["Myers, Christopher Allan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2008-08-28T21:35:31Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2008-08-28T21:35:31Z"]},{"key":"dc:date.issued","label":"Date","values":["2002"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Ecology, Evolution, and Behavior"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["The University of Texas at Austin"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright is held by the author. 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To investigate how CYT-18 stabilizes the active RNA structure, I used an Escherichia coli genetic assay with the phage T4 td intron to systematically test the ability of the CYT-18 protein to compensate for structural defects in the P7 region of the group I intron core. P7 is a long-range base-pairing interaction of the P3-P9 domain that forms the binding site for the splicing co-factor guanosine. My results show that CYT-18 can suppress numerous mutations that impair the self-splicing of the td intron, including mutations that disrupt base-pairing within the P7 region. CYT-18 suppressed mutations of phylogenetically conserved nucleotide residues at all positions tested, except for the universally conserved G-residue at the guanosine-binding site. Structure mapping experiments with some selected mutant introns showed that the P7 mutations impaired the formation of both P7 and P3, thereby grossly disrupting the P3-P9 domain. Previous work suggested that CYT-18 recognizes a conserved tRNA-like structure of the group I intron catalytic core. I used directed hydroxyl radical cleavage assays to show that the nucleotide-binding fold and C-terminal domains of CYT-18 interact with the expected group I intron cognates of the aminoacyl-acceptor stem and D-anticodon arms, respectively. Further, three-dimensional graphic modeling, supported by biochemical data, shows that conserved regions of group I introns can be superimposed over interacting regions of the tRNA in a Thermus thermophilus TyrRS/tRNATyr cocrystal structure."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["electronic"]},{"key":"dc:title","label":"Title","values":["Interaction of the Neurospora crassa mitochondrial tyrosyl-tRNA synthetase with group I intron RNAs"]}]}],"canonical_facts":{"dc:contributor.advisor":["Lambowitz, Alan"],"dc:creator":["Myers, Christopher Allan"],"dc:date.accessioned":["2008-08-28T21:35:31Z"],"dc:date.available":["2008-08-28T21:35:31Z"],"dc:date.issued":["2002"],"dc:description.abstract":["The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase, or CYT-18 protein, functions in splicing group I introns by promoting the formation of the catalytically active structure of the intron RNA. To investigate how CYT-18 stabilizes the active RNA structure, I used an Escherichia coli genetic assay with the phage T4 td intron to systematically test the ability of the CYT-18 protein to compensate for structural defects in the P7 region of the group I intron core. P7 is a long-range base-pairing interaction of the P3-P9 domain that forms the binding site for the splicing co-factor guanosine. My results show that CYT-18 can suppress numerous mutations that impair the self-splicing of the td intron, including mutations that disrupt base-pairing within the P7 region. CYT-18 suppressed mutations of phylogenetically conserved nucleotide residues at all positions tested, except for the universally conserved G-residue at the guanosine-binding site. Structure mapping experiments with some selected mutant introns showed that the P7 mutations impaired the formation of both P7 and P3, thereby grossly disrupting the P3-P9 domain. Previous work suggested that CYT-18 recognizes a conserved tRNA-like structure of the group I intron catalytic core. I used directed hydroxyl radical cleavage assays to show that the nucleotide-binding fold and C-terminal domains of CYT-18 interact with the expected group I intron cognates of the aminoacyl-acceptor stem and D-anticodon arms, respectively. Further, three-dimensional graphic modeling, supported by biochemical data, shows that conserved regions of group I introns can be superimposed over interacting regions of the tRNA in a Thermus thermophilus TyrRS/tRNATyr cocrystal structure."],"dc:format.medium":["electronic"],"dc:identifier":["b57170137"],"dc:identifier.uri":["http://hdl.handle.net/2152/807"],"dc:language.iso":["eng"],"dc:rights":["Copyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works."],"dc:title":["Interaction of the Neurospora crassa mitochondrial tyrosyl-tRNA synthetase with group I intron RNAs"],"thesis:degree_discipline":["Ecology, Evolution, and Behavior"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["The University of Texas at Austin"]},"updated_at":"2026-07-24T05:01:00Z"}