Nonhistone proteins HMG1 and HMG2 unwind DNA double helix

Kashayar Javaherian, Mohamad Sadeghi, Leroy-Fong Liu

研究成果: 雜誌貢獻文章

77 引文 斯高帕斯(Scopus)

摘要

In a previous communication we have shown that both HMG1 and HMG2 non-histone proteins change the DNA helical structure and the binding of HMG1 and HMG2 to DNA induces a net unwinding equivalent of DNA double helix (Javaherian, K., Liu, L. F. and Wang, J. C. (1978) Science, 199, 1345-1346). Employing melting absorption technique, we now show that in the presence of salt HMG1 and HMG2 destabilize DNA whereas in the absence of salt, they both stabilize DNA molecules. Consequently the folded structure of HMG must play an important role in melting DNA. Furthermore, by measuring topological winding number using competition unwinding experiments, we conclude that HMG1 has a higher affinity for a single-stranded DNA relative to double-stranded DNA. These results together suggest that HMG1 and HMG2 unwind DNA double helix by local denaturation of the DNA base pairs. The net unwinding angles have been measured to be 22° and 26° per molecule of HMG1 and HMG2 respectively.

原文英語
頁(從 - 到)3569-3580
頁數12
期刊Nucleic Acids Research
6
發行號11
DOIs
出版狀態已發佈 - 八月 10 1979
對外發佈Yes

    指紋

ASJC Scopus subject areas

  • Statistics, Probability and Uncertainty
  • Applied Mathematics
  • Health, Toxicology and Mutagenesis
  • Toxicology
  • Genetics(clinical)
  • Genetics

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