topoisomerases and gyrase

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JackBean
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topoisomerases and gyrase

Post by JackBean » Wed Apr 07, 2010 2:00 pm

Hi,
I'm little confused now.
here under 'Inhibition by antibiotics' part
wiki wrote:Gyrase is present in prokaryotes and some eukaryotes

But both in Alberts' The Cell and Voet's Biochemistry is written, that gyrase is prokaryotic only. E.g. in Voet is specifically:
The prokaryotic type II topoisomerase known as DNA gyrase...

So, I'm confused, whether is gyrase present in eukaryotes also and/or what is the difference between TOPOII and gyrase, or what makes the difference.

The other thing is, on other wiki page, there is:
an N-terminal GHKL ATPase domain (for Gyrase, Hsp, Kinase and MutL)

which sounds to me, that MutL is TOPOII too, but it's supposed to make one-strand breaks, while TOPOIIs should do double-strand breaks only, right?

Thanks for clarification
Tomas
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

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MrMistery
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Post by MrMistery » Thu Apr 08, 2010 12:32 am

gyrase is a special kind of topoII that is present in bacteria to introduce negative supercoils into the DNA. Eukaryotes have nucleosomes to introduce the negative supercoils, so they don't need to have a girase.
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

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