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Sequence-specific B-DNA flexibility modulates Z-DNA formation.

ABSTRACT: Conversion of right-handed B-DNA into left-handed Z-DNA is one of the largest structural transitions in biology that plays fundamental roles in gene expression and regulation. Z-DNA segments must form within genomes surrounded by a sea of B-DNA and require creation of energetically costly B/Z junctions. Here, we show using a combination of natural abundance NMR R(1?) carbon relaxation measurements and CD spectroscopy that sequence-specific B-DNA flexibility modulates the thermodynamic propensity to form Z-DNA and the location of B/Z junctions. We observe sequence-specific flexibility in B-DNA spanning fast (ps-ns) and slow (?s-ms) time scales localized at the site of B/Z junction formation. Further, our studies show that CG-repeats play an active role tuning this intrinsic B-DNA flexibility. Taken together, our results suggest that sequence-specific B-DNA flexibility may provide a mechanism for defining the length and location of Z-DNA in genomes.

SUBMITTER: Bothe JR

PROVIDER: S-EPMC3319140 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature

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Sequence-specific B-DNA flexibility modulates Z-DNA formation.

Bothe Jameson R JR Lowenhaupt Ky K Al-Hashimi Hashim M HM

Journal of the American Chemical Society 20110128 7

Conversion of right-handed B-DNA into left-handed Z-DNA is one of the largest structural transitions in biology that plays fundamental roles in gene expression and regulation. Z-DNA segments must form within genomes surrounded by a sea of B-DNA and require creation of energetically costly B/Z junctions. Here, we show using a combination of natural abundance NMR R(1ρ) carbon relaxation measurements and CD spectroscopy that sequence-specific B-DNA flexibility modulates the thermodynamic propensity ...[more]

PMID: 21275369

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