In a transversal section:
A-form: there is a central empty space, sugars and phosphates are at the margns and the nitrogen bases are towards the center
B-form: nitrogen bases are towards the center and the phosphates and sugars towards the margins(outside) of the macromolecule. The centre is filled with the nitrogen bases, there is no space
Z-form: appears as the compenents were distributed all around the matrix of the helix, with no specific domains. Actually the sugars and phosphates are towards the centre and the N bases on the outside.
Is this enough info or do you need more? cause i am lazy and do not want to write things without a point..
allright.p-form is found in vitro,on artificial xtension.this is all i know.can u make out sumthin’ of it?? 😆
DNA undergoes a stretching phase transition at a force of 65 pN; above this force, DNA is thought to take the form that Linus Pauling originally hypothesized, with the phosphates in the middle and bases splayed outward. This proposed structure for overstretched DNA has been called “P-form DNA,” in honor of Pauling.
