Interaction of the Dye Ethidium Bromide with DNA Containing Guanine Repeats

Qiu Guo, Luis A. Marky, Neville R. Kallenbach, Min Lu

Research output: Contribution to journalArticle

109 Citations (Scopus)

Abstract

DNA containing one or more copies of the motifs repeated in telomere sequences has unusual conformational properties. The isolated sequence from the protozoan Oxytricha, dT4G4has the potential to form tetramers in the presence of sodium or potassium ions. We report here that these tetramers bind ethidium tightly, with an interaction that fulfills several criteria for an intercalative mechanism in the G sequence. By contrast, the 4-fold tandem repeat of this subunit, d(T4G4)4, does not interact specifically with ethidium in the presence of Na+. This difference might have a simple structural basis: the tetramer of dT4G4forms a stack of four G-quartets in the presence of Na+or K+, whereas the constraint imposed by the T4 “tethers” in the repeat d(T4G4)4 allows only two layers to form in the presence of Na+. In the presence of sufficient K+, the latter can partially form a four-layer G-quartet structure, which interacts with ethidium. This idea is supported by analysis of a “relaxed” sequence, dT4G4(T7G4)3, which allows formation of four G-quartets and binds ethidium in the presence of Na+as well as K+. Ethidium (and intercalators generally) should thus be able to retard or inhibit the action of telomerase in the presence of K+.

Original languageEnglish (US)
Pages (from-to)2451-2455
Number of pages5
JournalBiochemistry
Volume31
Issue number9
DOIs
StatePublished - Feb 1 1992

Fingerprint

Ethidium
Guanine
Coloring Agents
DNA
Oxytricha
Intercalating Agents
Tandem Repeat Sequences
Telomerase
Telomere
Potassium
Sodium
Ions

ASJC Scopus subject areas

  • Biochemistry

Cite this

Interaction of the Dye Ethidium Bromide with DNA Containing Guanine Repeats. / Guo, Qiu; Marky, Luis A.; Kallenbach, Neville R.; Lu, Min.

In: Biochemistry, Vol. 31, No. 9, 01.02.1992, p. 2451-2455.

Research output: Contribution to journalArticle

Guo, Qiu ; Marky, Luis A. ; Kallenbach, Neville R. ; Lu, Min. / Interaction of the Dye Ethidium Bromide with DNA Containing Guanine Repeats. In: Biochemistry. 1992 ; Vol. 31, No. 9. pp. 2451-2455.
@article{46f92c7e4c3b4ab1bed943d73903eea2,
title = "Interaction of the Dye Ethidium Bromide with DNA Containing Guanine Repeats",
abstract = "DNA containing one or more copies of the motifs repeated in telomere sequences has unusual conformational properties. The isolated sequence from the protozoan Oxytricha, dT4G4has the potential to form tetramers in the presence of sodium or potassium ions. We report here that these tetramers bind ethidium tightly, with an interaction that fulfills several criteria for an intercalative mechanism in the G sequence. By contrast, the 4-fold tandem repeat of this subunit, d(T4G4)4, does not interact specifically with ethidium in the presence of Na+. This difference might have a simple structural basis: the tetramer of dT4G4forms a stack of four G-quartets in the presence of Na+or K+, whereas the constraint imposed by the T4 “tethers” in the repeat d(T4G4)4 allows only two layers to form in the presence of Na+. In the presence of sufficient K+, the latter can partially form a four-layer G-quartet structure, which interacts with ethidium. This idea is supported by analysis of a “relaxed” sequence, dT4G4(T7G4)3, which allows formation of four G-quartets and binds ethidium in the presence of Na+as well as K+. Ethidium (and intercalators generally) should thus be able to retard or inhibit the action of telomerase in the presence of K+.",
author = "Qiu Guo and Marky, {Luis A.} and Kallenbach, {Neville R.} and Min Lu",
year = "1992",
month = "2",
day = "1",
doi = "10.1021/bi00124a002",
language = "English (US)",
volume = "31",
pages = "2451--2455",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "9",

}

TY - JOUR

T1 - Interaction of the Dye Ethidium Bromide with DNA Containing Guanine Repeats

AU - Guo, Qiu

AU - Marky, Luis A.

AU - Kallenbach, Neville R.

AU - Lu, Min

PY - 1992/2/1

Y1 - 1992/2/1

N2 - DNA containing one or more copies of the motifs repeated in telomere sequences has unusual conformational properties. The isolated sequence from the protozoan Oxytricha, dT4G4has the potential to form tetramers in the presence of sodium or potassium ions. We report here that these tetramers bind ethidium tightly, with an interaction that fulfills several criteria for an intercalative mechanism in the G sequence. By contrast, the 4-fold tandem repeat of this subunit, d(T4G4)4, does not interact specifically with ethidium in the presence of Na+. This difference might have a simple structural basis: the tetramer of dT4G4forms a stack of four G-quartets in the presence of Na+or K+, whereas the constraint imposed by the T4 “tethers” in the repeat d(T4G4)4 allows only two layers to form in the presence of Na+. In the presence of sufficient K+, the latter can partially form a four-layer G-quartet structure, which interacts with ethidium. This idea is supported by analysis of a “relaxed” sequence, dT4G4(T7G4)3, which allows formation of four G-quartets and binds ethidium in the presence of Na+as well as K+. Ethidium (and intercalators generally) should thus be able to retard or inhibit the action of telomerase in the presence of K+.

AB - DNA containing one or more copies of the motifs repeated in telomere sequences has unusual conformational properties. The isolated sequence from the protozoan Oxytricha, dT4G4has the potential to form tetramers in the presence of sodium or potassium ions. We report here that these tetramers bind ethidium tightly, with an interaction that fulfills several criteria for an intercalative mechanism in the G sequence. By contrast, the 4-fold tandem repeat of this subunit, d(T4G4)4, does not interact specifically with ethidium in the presence of Na+. This difference might have a simple structural basis: the tetramer of dT4G4forms a stack of four G-quartets in the presence of Na+or K+, whereas the constraint imposed by the T4 “tethers” in the repeat d(T4G4)4 allows only two layers to form in the presence of Na+. In the presence of sufficient K+, the latter can partially form a four-layer G-quartet structure, which interacts with ethidium. This idea is supported by analysis of a “relaxed” sequence, dT4G4(T7G4)3, which allows formation of four G-quartets and binds ethidium in the presence of Na+as well as K+. Ethidium (and intercalators generally) should thus be able to retard or inhibit the action of telomerase in the presence of K+.

UR - http://www.scopus.com/inward/record.url?scp=0026608237&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026608237&partnerID=8YFLogxK

U2 - 10.1021/bi00124a002

DO - 10.1021/bi00124a002

M3 - Article

C2 - 1547228

AN - SCOPUS:0026608237

VL - 31

SP - 2451

EP - 2455

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 9

ER -