Why does negative supercoiling favor unwinding?

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SoyeongPark
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Why does negative supercoiling favor unwinding?

Post by SoyeongPark » Sat Mar 13, 2010 10:23 am

Hi,

I was just studying about RNA polymerase and am a little bit confused because of this:
"Negative supercoiling of circular DNA favors the transcription of genes because it facilitates unwinding."
Why does negative supercoiling favor unwinding?
Please help me

Thank you in advance :D

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JackBean
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Post by JackBean » Sun Mar 14, 2010 8:20 am

because when unwinding DNA double strand, you have to spin it (along its length). So, if is it already spined (supercoiled) in the same way, you will get stucked (and need topoisomerases), on the other hand, if is it spined in opposite way, you will compansate for it and it will be fine ;)

that's my explanation, but I'm not sure
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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