B-Z DNA Junctions Deciphered
New anti-cancer drugs blocking the formation of Z-DNA are on the horizon. Korean researchers headed by Prof. Kim Kyeong-kyu at Sungkyunkwan University have deciphered the three-dimensional structure that forms the junction between B- and Z-DNA. Z-DNA helps to control gene activity and has been implicated in cancer etiology.
Excerpt from the Nature Editor’s Summary:
This week’s cover story is the determination of the crystal structure of the junction between left-handed DNA and ‘normal’, right-handed DNA or B-DNA. Each time a DNA segment turns to Z-DNA, two of these B-Z junctions are created. …The three-dimensional structure shows that the junction is very tight, and that a base pair is pushed out of the double helix, one base on each side of the junction. This adjustment maintains the base stacking that is a major stabilizing factor. These displaced bases may be sites for DNA modification.
The Korea Times, October 20, 2005
