How does circular DNA wrap around a histone to form a chromosome?

[gauss44]

How does circular DNA wrap around a histone to form a chromosome? Or does it?

I am having a hard time visualizing this for any sort of circular DNA: prokaryotes, mitochondria, etc.

(This question was inspired by my reading about biology and reading that circular DNA does, in fact, form chromosomes. So, now I'm wondering how?)

 

[tiny-tim]

come on, guys …

somebody must know the answer to this! ​

 

[SW VandeCarr]

come on, guys …

somebody must know the answer to this! ​

I'm not a biologist, but this set of images from missouri.edu seems to explain it. I have no reason to think it's inaccurate.

http://web.missouri.edu/~vandorens/Biochem8240/lectures/Nucl_acid_supercoil_1oct12.pdf

 

[chemisttree]

How does circular DNA wrap around a histone to form a chromosome? Or does it?

It doesn't wrap around a histone. It is compact in shape with the help of a variety of proteins such as HU.
http://www.nature.com/scitable/topi...g-in-prokaryotes-the-circular-chromosome-9113

 

[Manish7]

How does circular DNA wrap around a histone to form a chromosome?

Histone are proteins made up of amino acids (basic) ex. lysine and arginine , that are positively charged.on the other hand DNA contains phosphorus backbone(PO4 3-). so this is an electrostatic attraction and nothing else.
also, some transcription regulatory machinery regulates this wrapping otherwise the length of DNA is 2.2m in Humans.
Due to this euchromatin and Heterochromatin is seen under Electrophoresis and DNA banding patterns.