From the article in the nih.gov link below: "The *** E. coli *** strains used in this study and their relevant genotype are detailed in Supplementary Table S1." http://en.wikipedia.org/wiki/Escherichia_coli "The first complete DNA sequence of an E. coli genome ... was published in 1997. It was found to be a *** circular *** DNA molecule 4.6 million base pairs in length, containing 4288 annotated protein-coding genes (organized into 2584 operons), seven ribosomal RNA (rRNA) operons, and 86 transfer RNA (tRNA) genes." E. coli has *** circular *** DNA. Human nuclear (non-mitochondrial) DNA isn't circular. At 09:41 AM 12/28/2012, Michael Kleber wrote:
On Fri, Dec 28, 2012 at 11:56 AM, Henry Baker <hbaker1@pipeline.com> wrote:
I don't know what % of the time (human nuclear--i.e., non-mitochondrial)
DNA spends doing recombination, but I would guess/hope very small. During the rest of the time, it is my understanding that there aren't any knots in this DNA.
I'm sorry, I didn't realize we were still arguing about this question of fact. Let me re-post the link from up-thread, along with the beginning of the article this time.
http://www.ncbi.nlm.nih.gov/pubmed/22187153 "Topo IV is the topoisomerase that knots and unknots sister duplexes during DNA replication"