Z-DNA-induced super-transport of energy within genomes

Spontaneous transitions of genomic DNA segments from right-handed B-DNA into the left-handed, high-energy Z conformation are unstable within topologically relaxed DNA molecules, such as mammalian chromosomes. Here we show, from direct application of the principles of statistical physics with a promoter region in the mouse genome as a representative example, that the life span for this alternate DNA conformation may be much smaller than the characteristic time of thermal fluctuations that cause the B-to-Z transition. Surprisingly, such a short existence of Z-DNA is important because it can be responsible for super-transport of energy within a genome. This type of energy transport can be utilized by a cell to communicate information about the state of particular chromatin domains within chromosomes or as a buffer against genome instability.