[laura.g.berger]

Hello, guys.
I'm new in this forum and i don't understand very much of chemistry. I would like to know if is possible i change the two atoms of
oxigen in the phosphate group of the nucleotides of the DNA for some other atoms. Those who does a double bond with the phosphorus and the other one who does a simple bond with phosphorus.
I would like to know too if these changes will affect the geometry helicoidal of the DNA.

This website will help you to see better these atoms that i'm talking about:
http://www.uic.edu/classes/phys/phys461/phys450/ANJUM04/

Thank you very much for your help.

[discodermolide]

You can replace any of the atoms surrounding the phosphorus with others, especially carbon or sulphur.
Any changes you make will affect the geometry of DNA.
You can even replace the phosphorus atom with aesenci according to a recent publication, but the exact effects on DNA I do not know.

[Babcock_Hall]

The replacement of oxygen with sulfur changes the speed with which nucleases can cleave the phosphodiester bond.  This technique has a long history in vitro, but apparently this can happen in some bacteria (which I did not know):  http://www.pnas.org/content/108/7/2963.full