Helical Repeats of Left-Handed DNA - Open Journal of Molecular and Integrative Physiology

OJMIP > Vol.4 No.2, May 2014

Helical Repeats of Left-Handed DNA ()

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DOI: 10.4236/ojmip.2014.42003 7,429 Downloads 9,814 Views Citations

Author(s)

Youcheng Xu

Affiliation(s)

UT Southwestern Medical Center at Dallas, Dallas, USA.

ABSTRACT

DNA is generally assumed as a right-handed double helix and Z-DNA is a special kind of left-handed DNA infrequently found in nature. However, the finding of a zero linking number topoisomer supports a hypothesis that the two strands of DNA are winding ambidextrously, rather than plectonemically. It logically leads to a notion that the left-handed DNA is as common as right-handed DNA and the amount of left-handed DNA in a positively supercoiled plasmid prevails that of the right-handed DNA. In this report, the helical repeat of left-handed DNA, 12 bp per turn, was determined by a new method. How the positively supercoiled DNA was generated in hyperthermophiles and why their DNA can withstand the extreme high temperature are answered from an alternative theory.

KEYWORDS

Left-Handed DNA, Ambidextrous Double Helix, Linking Number, Positive Supercoiling, Hyperthermophiles

Share and Cite:

Xu, Y. (2014) Helical Repeats of Left-Handed DNA. Open Journal of Molecular and Integrative Physiology, 4, 20-26. doi: 10.4236/ojmip.2014.42003.

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