J 2000

An A-type Double Helix of DNA Having B-type Puckering of the Deoxyribose Rings

TRANTÍREK, Lukáš, Richard ŠTEFL, Michalea VORLÍČKOVÁ, Jaroslav KOČA, Vladimír SKLENÁŘ et. al.

Basic information

Original name

An A-type Double Helix of DNA Having B-type Puckering of the Deoxyribose Rings

Authors

TRANTÍREK, Lukáš (203 Czech Republic), Richard ŠTEFL (203 Czech Republic), Michalea VORLÍČKOVÁ, Jaroslav KOČA (203 Czech Republic), Vladimír SKLENÁŘ (203 Czech Republic, guarantor) and Jaroslav KYPR

Edition

Journal of Molecular Biology, USA, Academic Press, 2000, 0022-2836

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10600 1.6 Biological sciences

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 5.388

RIV identification code

RIV/00216224:14310/00:00000057

Organization unit

Faculty of Science

UT WoS

000086345700006

Keywords in English

DNA; A-type double helix; B-type deoxyribose pucker; buckled CG step; minor group widening
Změněno: 26/1/2007 17:24, prof. Mgr. Richard Štefl, Ph.D.

Abstract

V originále

DNA usually adopts structure B in aqueous solution, while structure A is preferred in mixtures of trifluoroethanol (TFE) with water. However, the octamer d(CCCCGGGG) and other d(CnGn) fragments of DNA provide CD spectra that suggest that the base-pairs are stacked in an A-like fashion even in aqueous solution. Yet, d(CCCCGGGG) undergoes a cooperative TFE-induced transition into structure A, indicating that an important part of the aqueous duplex retains structure B. NMR spectroscopy shows that puckering of the deoxyribose rings is of the B-type. Hence, combination of the information provided by CD spectroscopy and NMR spectroscopy suggests an unprecedented double helix of DNA in which A-like base stacking is combined with B-type puckering of the deoxyribose rings. In order to determine whether this combination is possible, we used molecular dynamics to simulate the duplex of d(CCCCGGGG). Remarkably, the simulations, completely unrestrained by the experimental data, provided a very stable double helix of DNA, exhibiting just the intermediate B/A features described above. The double helix contained well-stacked guanine bases but almost unstacked cytosine bases. This generated a hole in the double helix center, which is a property characteristic for A-DNA, but absent from B-DNA. The minor groove was narrow at the double helix ends but wide at the central CG step where the Watson- Crick base-pairs were buckled in opposite directions. The base-pairs stacked tightly at the ends but stacking was loose in the duplex center. The present double helix, in which A-like base stacking is combined with B-type sugar puckering, is relevant to replication and transcription because both of these phenomena involve a local B-to-A transition.

In Czech

DNA usually adopts structure B in aqueous solution, while structure A is preferred in mixtures of trifluoroethanol (TFE) with water. However, the octamer d(CCCCGGGG) and other d(CnGn) fragments of DNA provide CD spectra that suggest that the base-pairs are stacked in an A-like fashion even in aqueous solution. Yet, d(CCCCGGGG) undergoes a cooperative TFE-induced transition into structure A, indicating that an important part of the aqueous duplex retains structure B. NMR spectroscopy shows that puckering of the deoxyribose rings is of the B-type. Hence, combination of the information provided by CD spectroscopy and NMR spectroscopy suggests an unprecedented double helix of DNA in which A-like base stacking is combined with B-type puckering of the deoxyribose rings. In order to determine whether this combination is possible, we used molecular dynamics to simulate the duplex of d(CCCCGGGG). Remarkably, the simulations, completely unrestrained by the experimental data, provided a very stable double helix of DNA, exhibiting just the intermediate B/A features described above. The double helix contained well-stacked guanine bases but almost unstacked cytosine bases. This generated a hole in the double helix center, which is a property characteristic for A-DNA, but absent from B-DNA. The minor groove was narrow at the double helix ends but wide at the central CG step where the Watson- Crick base-pairs were buckled in opposite directions. The base-pairs stacked tightly at the ends but stacking was loose in the duplex center. The present double helix, in which A-like base stacking is combined with B-type sugar puckering, is relevant to replication and transcription because both of these phenomena involve a local B-to-A transition.

Links

VS96095, research and development project
Name: Laboratoř struktury a dynamiky biomolekul
Investor: Ministry of Education, Youth and Sports of the CR, Laboratory of Structure and Dynamics of Biomolecules