Loops and Stretching

'Stretch a DNA Loop, Turn Off Proteins' reveals how the regulation of gene expression can be a consequence of the mechanical structure of DNA. Specifically discussed are loops, the stretching of DNA and proteins. A paragraph from the linked article:

"Biologists have discovered that the physical manifestation of DNA loops are a consequence of many biochemical processes in the cell, such as the regulation of gene expression. In other words, these loops indicate the presence of enzymes or other proteins that are turned on. Now physicists at the University of California, San Diego have discovered that stretching the DNA molecule can also turn off the proteins known to cause loops in DNA."