In 1979, Rich and co-workers at MIT accidentally grew a crystal of Z-DNA.[1] This was the first crystal structure of any form of DNA. After 26 years of attempts, Rich et al. finally crystallised the junction box of B- and Z-DNA. Their results were published in an October 2005 Nature journal.[2] Whenever Z-DNA forms, there must be two junction boxes that allow the flip back to the canonical B-form of DNA.
↑ Wang AHJ, Quigley GJ, Kolpak FJ, Crawford JL, van Boom JH, Van der Marel G, and Rich A (1979). Molecular structure of a left-handed double helical DNA fragment at atomic resolution. Nature (London) 282:680-686.
↑ Ha SC, Lowenhaupt K, Rich A, Kim YG, and Kim KK (2005). Crystal structure of a junction between B-DNA and Z-DNA reveals two extruded bases. Nature437:1183-1186.
Selected publications
Brown BA II, Lowenhaupt K, Wilbert CM, Hanlon EB, Rich A (2000). The Za domain of the editing enzyme dsRNA adenosine deaminase binds left-handed Z-RNA as well as Z-DNA. Proc Nat'l Acad Sci USA, 97:13531-13586.
Kim Y-G, Lowenhaupt K, Maas S, Herbert A, Schwartz T, Rich A (2000). The Zab domain of the human RNA editing enzyme ADAR1 recognizes Z-DNA when surrounded by B-DNA. J Biol Chem, 275:26828-26833.
Schwartz T, Rould MA, Lowenhaupt K, Herbert A, Rich A (1999). Crystal structure of the Za domain of the human editing enzyme ADAR1 bound to left-handed Z-DNA. Science, 284:1841-1845.