DNA Day DNA Day National DNA Day is a holiday celebrated on April 25. It commemorates the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin and colleagues published papers in the journal Nature on the structure of DNA. Furthermore, on that day in 2003 it was declared that the Human Genome Project was very close to complete, and "the remaining tiny gaps [we]re considered too costly to fill." In the United States, DNA Day was first celebrated on April 25, 2003 by proclamation of both the Senate and the House of Representatives. However, they only declared a one-time
DNA supercoil and once again it is (in part at least) relieved by superhelicity, but this time in the opposite direction ("i.e.," left-handed or "positive"). Each left-handed tertiary supertwist removes a single, now "undesirable" right-handed Watson-Crick secondary twist. The titration ends at pH 13, where Form IV appears. DNA supercoil DNA supercoiling refers to the over- or under-winding of a DNA strand, and is an expression of the strain on that strand. Supercoiling is important in a number of biological processes, such as compacting DNA, and by regulating access to the genetic code, DNA supercoiling strongly affects DNA metabolism and possibly gene