Although the proteins that cause the E.coli chromosome to the coil are not histones, what property would you expect them to share with histones, given their ability to bind to DNA (see Figure 5.14)?

E coli are the bacterium that is present in the human intestine. It is a gram-negative and rod-shaped bacterium. It has only one chromosome that possesses a circular plasmid.

There are coding and non-coding regions in the E.coli chromosome. The length of the E.coli chromosome is about 4,600 Kb.

DNA-binding proteins are the component that keeps the DNA in a compact condition. Histones are binding proteins present in eukaryotes. These are not found in the prokaryotic organism.

E.colidoes not have histones protein, but it possesses the amino acids present in the histone proteins.The amino acids are lysine and arginine. These are positively charged amino acid that forms the interaction with the negatively charged component of DNA.

It forms a weaker bond with the sugar-phosphate backbone of the DNA. The binding structure present in E.coli has similar structural composition compared to the histones and can bind with DNA.

Hence, the E.coli bacterium has amino acids such as lysine and arginine that exhibit similar mechanisms like histones to bind with the DNA.