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. 1996 Aug 15;24(16):3208–3215. doi: 10.1093/nar/24.16.3208

The DNA supercoiling architecture induced by the transcription factor xUBF requires three of its five HMG-boxes.

V Y Stefanovsky 1, D P Bazett-Jones 1, G Pelletier 1, T Moss 1
PMCID: PMC146074  PMID: 8774902

Abstract

The formation of a near complete loop of DNA is a striking property of the architectural HMG-box factor xUBF. Here we show that DNA looping only requires a dimer of Nbox13, a C-terminal truncation mutant of xUBF containing just HMG-boxes 1-3. This segment of xUBF corresponds to that minimally required for activation of polymerase I transcription and is sufficient to generate the major characteristics of the footprint given by intact xUBF. Stepwise reduction in the number of HMG-boxes to less than three significantly diminishes DNA bending and provides an estimate of bend angle for each HMG-box. Together the data indicate that a 350 +/- 16 degree loop in 142 +/- 30 bp of DNA can be induced by binding of the six HMG-boxes in an Nbox13 dimer and that DNA looping is probably achieved by six in-phase bends. The positioning of each HMG-box on the DNA does not predominantly involve DNA sequence recognition and is thus an intrinsic property of xUBF.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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