Which of the following is not true of the N terminal tail of these histones? The core histones are small, basic proteins that have a globular domain at the C-terminus and a long extended conformation at the N-terminus.
A. It is subject to a covalent modifications B. It extends out of the nucleosome core C. It binds to DNA in a sequence-specific manner D. It helps DNA pack tightly E. It contains lysine residues
The answer to this question is option C
Histones are rich in the amino acids lysine and arginine. H1 binds to the nucleosome and to “linker DNA,” stabilizing the chromatin fiber. Histones are positively charged and they bind to negatively charged DNA to keep DNA tightly packed together. Negatively charged DNA loops twice around positively charged histone octamer, to form nucleosome which appears as “beads on a string.”
Histones do not bind to DNA in a sequence specific manner. % types of histones have been identified - H1, H2A, H2, H3 and H4.
H1 serves as linker histones. H1 binds to the nucleosome and to “linker DNA,” thereby stabilizing the chromatin fiber. While H2B, H3 and H4are associated with DNA to form nucleosomes.