Question

What is the charge characteristic of DNA packaging proteins in both prokaryotes and eukaryotes?

Options

• Both use positively charged proteins (HU proteins in prokaryotes; histones in eukaryotes)

• Prokaryotes use positively charged proteins; eukaryotes use negatively charged proteins

• Charge is irrelevant to DNA packaging

• Both use negatively charged proteins

Answer 1

Both prokaryotic and eukaryotic DNA packaging proteins are positively charged. In prokaryotes, HU proteins are positively charged histone-like proteins that assist supercoiling. In eukaryotes, histones (especially rich in lysine and arginine) are positively charged, allowing them to bind electrostatically to the negatively charged phosphate backbone of DNA.