I'm looking for data - maybe CHP^2 data that shows chromatin binding to a prokaryotic genome under some specific conditions. Can anyone point me to a source?
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1$\begingroup$ Well, a byproduct of the fact that prokaryotes do not have nucleosomes, is that they don't have chromatin either. Compaction is achieved through supercoiling of the genophore. Do you mean binding of a protein to prokaryotic DNA ? $\endgroup$– agrimaldiCommented Dec 15, 2011 at 23:51
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$\begingroup$ @agrimaldi: That is not exactly the case. Some prokaryotes have nucleosome-like structures. $\endgroup$– GWWCommented Dec 16, 2011 at 3:14
1 Answer
A large number of prokaryotes do indeed have nucleosome-like structures. The most well studied is H-NS in E. coli, Salmonella and some other deltaproteobacteria. H-NS like molecules have also been found in mycoplasma (Lsr2). One of its roles is to bind AT-rich DNA and silence transcription. The binding is usually to suppress the expression of foreign DNA which tends to have a lower GC content than the host organism. There is a great paper that did ChIP on ChIP with H-NS in Salmonella by Navarre et al in Science (Pubmed ID: 1676311).
As a side note H-NS does compact DNA and there is a paper by Dame et al. that demonstrates it with atomic force microscopy.
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$\begingroup$ @agrimaldi: There's a lot of papers about H-NS and H-NS like proteins, it's very interesting. $\endgroup$– GWWCommented Dec 16, 2011 at 6:40
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$\begingroup$ I was just reading this paper: In making the case for chromatin binding, to the bacterial genome, it seems like the nucleate at supercoiling regions but then may migrate. The GC content idea sounds intriguing, but wondering if there is any more specificity the chromatin exhibits upon binding. Genome biology, 5(12), 252. doi:10.1186/gb-2004-5-12-252 $\endgroup$– shigetaCommented Dec 20, 2011 at 17:54