Question

What would happen if histones were to be mutated and made rich in acidic amino acids such as aspartic acid and glutamic acid in place of basic amino acids such as lysine and arginine?

Answer 1

Aspartic and glutamic acid are acidic amino acids, while lysine and arginine are basic amino acids. Lysine and arginine carry positive charge on their side chains which is not the case with aspartic add and glutamic acid. DNA is negatively charged and hence is wrapped around the positively charge histone octamer. If acidic amino acids are present in histone because of mutation, DNA won't be able to wrap around itself. Thus, long strand of DNA will not be able to fit inside the small space in the nucleus. This will mean an end to nuclear organization which Is possible because of efficient packaging.