Guanine-rich sequences are vital components in the genomes of many organisms. For example, G-rich sequences are found in telomeres, fragile X locus, promoters, IgG switch regions, recombinational hot spots and the HIV RNA dimerization domain. The functions of these G-rich sequences rely in part on guanine self-recognition. G-rich sequences can adopt a quadruple helical conformation in the presence of specific monovalent and divalent metal cations which are also required for maintaining the quadruplex stability. The structural basis of the quadruplex is a cyclic Hoogsteen hydrogen bonded guanine tetrad known as the G-quartet. Sequences capable of forming G-quartets are classified as G-DNA. The family of G-DNA structures includes anti-parallel hairpin dimer conformations (G'2-DNA) and parallel tetramer conformations (G4-DNA). In this work we have employed the techniques of gel electrophoresis, UV spectroscopy and atomic force microscopy (AFM) to study a new G4-DNA nanostructure. The oligonucleotide d(GGGGTTGGGG) (Tet1.5) self-assembles into highly ordered filamentous polymers that we call G-wires. The self-assembly of Tet1.5 into G-wires is shown by gel electrophoresis to be highly ordered and dependent on specific metal cations. G-wires have characteristics that are unique to G-DNA. AFM analysis of G-wires complimented the electrophoretic studies and revealed the highly ordered structures to be filamentous polymers. G-wires exhibit resistance to distortion by the scanning probe that is related to their structural characteristics. This study indicates that G-wires could function as a scaffold enabling the controlled positioning of atoms and molecules in space, the primary goal of nanotechnology.
","abstract_html":"<p>Guanine-rich sequences are vital components in the genomes of many organisms. For example, G-rich sequences are found in telomeres, fragile X locus, promoters, IgG switch regions, recombinational hot spots and the HIV RNA dimerization domain. The functions of these G-rich sequences rely in part on guanine self-recognition. G-rich sequences can adopt a quadruple helical conformation in the presence of specific monovalent and divalent metal cations which are also required for maintaining the quadruplex stability. The structural basis of the quadruplex is a cyclic Hoogsteen hydrogen bonded guanine tetrad known as the G-quartet. Sequences capable of forming G-quartets are classified as G-DNA. The family of G-DNA structures includes anti-parallel hairpin dimer conformations (G'2-DNA) and parallel tetramer conformations (G4-DNA). In this work we have employed the techniques of gel electrophoresis, UV spectroscopy and atomic force microscopy (AFM) to study a new G4-DNA nanostructure. The oligonucleotide d(GGGGTTGGGG) (Tet1.5) self-assembles into highly ordered filamentous polymers that we call G-wires. The self-assembly of Tet1.5 into G-wires is shown by gel electrophoresis to be highly ordered and dependent on specific metal cations. G-wires have characteristics that are unique to G-DNA. AFM analysis of G-wires complimented the electrophoretic studies and revealed the highly ordered structures to be filamentous polymers. G-wires exhibit resistance to distortion by the scanning probe that is related to their structural characteristics. This study indicates that G-wires could function as a scaffold enabling the controlled positioning of atoms and molecules in space, the primary goal of nanotechnology.</p>","abstract_has_math":false,"creators":["Marsh, Thomas"],"institution":null,"degree_name":"Doctor of Philosophy","degree_level":"dissertation","degree_discipline":null,"degree_department":"Zoology and Genetics (Historical)","school":null,"contributors":[],"advisors":["Eric R. Henderson"],"committee_chairs":[],"committee_members":[],"year":1994,"date_issued":"1994","date_published":"1994","updated_at":"2026-07-24T02:39:41Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.31274/rtd-180813-10346"],"render_values":[{"text":"https://doi.org/10.31274/rtd-180813-10346","href":"https://doi.org/10.31274/rtd-180813-10346","code":true}]},{"key":"dc:identifier","label":"Identifier","values":["archive/lib.dr.iastate.edu/rtd/11291/"],"render_values":[{"text":"archive/lib.dr.iastate.edu/rtd/11291/","href":null,"code":true}]}]},"links":{"outbound_url":"https://dr.lib.iastate.edu/handle/20.500.12876/64532","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Eric R. 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For example, G-rich sequences are found in telomeres, fragile X locus, promoters, IgG switch regions, recombinational hot spots and the HIV RNA dimerization domain. The functions of these G-rich sequences rely in part on guanine self-recognition. G-rich sequences can adopt a quadruple helical conformation in the presence of specific monovalent and divalent metal cations which are also required for maintaining the quadruplex stability. The structural basis of the quadruplex is a cyclic Hoogsteen hydrogen bonded guanine tetrad known as the G-quartet. Sequences capable of forming G-quartets are classified as G-DNA. The family of G-DNA structures includes anti-parallel hairpin dimer conformations (G'2-DNA) and parallel tetramer conformations (G4-DNA). In this work we have employed the techniques of gel electrophoresis, UV spectroscopy and atomic force microscopy (AFM) to study a new G4-DNA nanostructure. The oligonucleotide d(GGGGTTGGGG) (Tet1.5) self-assembles into highly ordered filamentous polymers that we call G-wires. The self-assembly of Tet1.5 into G-wires is shown by gel electrophoresis to be highly ordered and dependent on specific metal cations. G-wires have characteristics that are unique to G-DNA. AFM analysis of G-wires complimented the electrophoretic studies and revealed the highly ordered structures to be filamentous polymers. G-wires exhibit resistance to distortion by the scanning probe that is related to their structural characteristics. This study indicates that G-wires could function as a scaffold enabling the controlled positioning of atoms and molecules in space, the primary goal of nanotechnology.
"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["G-wires: The growth and characterization of a G4-DNA nanostructure"]}]}],"canonical_facts":{"dc:contributor.advisor":["Eric R. Henderson"],"dc:contributor.department":["Zoology and Genetics (Historical)"],"dc:creator":["Marsh, Thomas"],"dc:date":["2018-08-23T17:36:04.000"],"dc:date.accessioned":["2020-06-30T07:11:43Z"],"dc:date.available":["2020-06-30T07:11:43Z"],"dc:date.issued":["1994"],"dc:description.abstract":["Guanine-rich sequences are vital components in the genomes of many organisms. For example, G-rich sequences are found in telomeres, fragile X locus, promoters, IgG switch regions, recombinational hot spots and the HIV RNA dimerization domain. The functions of these G-rich sequences rely in part on guanine self-recognition. G-rich sequences can adopt a quadruple helical conformation in the presence of specific monovalent and divalent metal cations which are also required for maintaining the quadruplex stability. The structural basis of the quadruplex is a cyclic Hoogsteen hydrogen bonded guanine tetrad known as the G-quartet. Sequences capable of forming G-quartets are classified as G-DNA. The family of G-DNA structures includes anti-parallel hairpin dimer conformations (G'2-DNA) and parallel tetramer conformations (G4-DNA). In this work we have employed the techniques of gel electrophoresis, UV spectroscopy and atomic force microscopy (AFM) to study a new G4-DNA nanostructure. The oligonucleotide d(GGGGTTGGGG) (Tet1.5) self-assembles into highly ordered filamentous polymers that we call G-wires. The self-assembly of Tet1.5 into G-wires is shown by gel electrophoresis to be highly ordered and dependent on specific metal cations. G-wires have characteristics that are unique to G-DNA. AFM analysis of G-wires complimented the electrophoretic studies and revealed the highly ordered structures to be filamentous polymers. G-wires exhibit resistance to distortion by the scanning probe that is related to their structural characteristics. This study indicates that G-wires could function as a scaffold enabling the controlled positioning of atoms and molecules in space, the primary goal of nanotechnology.
"],"dc:format.mimetype":["application/pdf"],"dc:identifier":["archive/lib.dr.iastate.edu/rtd/11291/"],"dc:identifier.doi":["https://doi.org/10.31274/rtd-180813-10346"],"dc:identifier.uri":["https://dr.lib.iastate.edu/handle/20.500.12876/64532"],"dc:language.iso":["en"],"dc:title":["G-wires: The growth and characterization of a G4-DNA nanostructure"],"dc:type":["dissertation"],"thesis:degree_level":["dissertation"],"thesis:degree_name":["Doctor of Philosophy"]},"updated_at":"2026-07-24T02:39:41Z"}