In which organisms or cell z DNA is present &is it responsible for any different functions?????

Answer 1

Z-DNA is a left-handed helical form of DNA in which the double helix winds to the left in a zig-zag pattern (instead of to the right, like the more common B-DNA form). A left-handed form of DNA found under physiological conditions in short GC segments that are methylated. It may be important in regulating gene expression in eukaryotes.

Z-DNA was the first crystal structure of a DNA molecule to be solved by Alexander Rich and co-workers in 1979 at MIT.
Z-DNA is quite different from the right-handed forms. This unique type of DNA forms under sequence-dependent conditions that require an alternating purine-pyrimidine sequence. Other chemical environmental factors favor the formation of Z-DNA such as high salt, the presence of some cations, and DNA supercoiling.While no definitive biological significance of Z-DNA has been found.
The left-handed form of DNA is less stable than the right-handed form, and it needs energy to be pushed into that form. One of the major sources for this energy comes from the movement of the enzyme that makes a copy of the genetic message which is then used in synthesizing proteins.

This enzyme, called RNA polymerase, makes messenger RNA by moving along the right-handed DNA duplex. However, as other researchers have shown, instead of rotating around the DNA, it plows straight through. This leaves behind it DNA in an underwound or negatively supercoiled form. It has been found that the energy of this negative supercoiling can stabilize left-handed Z-DNA. Formation of Z-DNA may act as a signal to the editing enzyme that the information in the DNA is to be modified."

When otherwise normal DNA adopts an unusual shape called Z-DNA, it can lead to the kind of genetic instability associated with cancers such as leukemia and lymphoma, according to a study by researchers at The University of Texas M. D. Anderson Cancer Center.

The study demonstrates for the first time that the oddly shaped DNA can cause DNA breaks in mammalian cells.

Interestingly, these sequences prone to forming Z-DNA are often found in genetic "hot spots," areas of DNA known to be prone to the genetic rearrangements associated with cancer. About 90 percent of patients with Burkitt's lymphoma, for example,have DNA breaks that map to regions with the potential to form these odd DNA structures. ZDNA itself can act as a mutagen, resulting in genetic instability.

Answer 2

DNA(Deoxy Rebon nucleic acid) is found in the cell of every living organism. It plays the most important role in carrying genetic information from parents to their offsprings. Tihs is also known as Heredity.

Answer 3

Every cell has DNA.

It is the characteristic of an Individual.

ie

All of my cell have same DNA, my blood relative can be also identified through DNA comparition.

Only identical twins will have same DNA.

Answer 4

DNA is found in all prokaryotes and eukaryotes organism, dna plays a crucial role in trasfer of genetic information , its sequence determine the protein to be synthesized and hence its functioning,now a days dna used to evaluate many probs...
used as probe in characterization of a sp.,
RDT,gene therapy,cloning, ....

Answer 5

DNA is the "blueprint of existence" - it codes for each little thing and each cellular that makes up an organism. DNA is needed for existence. by way of fact of this a mutation in DNA could reason risky outcomes.

Answer 6

DNA is present in all cells.