Researchers believe they have found a second code in DNA in addition to the genetic code. The genetic code specifies all the proteins that a cell makes. The second code, superimposed on the first, sets the placement of the nucleosomes, miniature protein spools around which the DNA is looped. The spools both protect and control access to the DNA itself.
The discovery, if confirmed, could open new insights into the higher order control of the genes, like the critical but still mysterious process by which each type of human cell is allowed to activate the genes it needs but cannot access the genes used by other types of cell.
Courtesy of Loren Williams/Chemistry and Biochemistry, Georgia Institute of Technology
In a living cell, the DNA double helix wraps around a nucleosome, above center, and binds to some of its proteins, known as histones.
This new discovery does not mean that the overlaying system stores new information, but that the nucleosomes regulate which genes are activated or actually used. This is very important for understanding how protiens "supervise" what the DNA actually does. jg
10:18:34 PM 
|
|
