Describe the features and function of HP1 in heterochromatin

Describe the features and function of HP1 in heterochromatin formation. Outline all of the players/roles and steps in the formation of the 30nm fiber. Is HP1 the same as Histone H1? Why or why not?

Solution

Hetrochromatin protein 1 HP 1 is a central factor in maintaining the heterochromatin state.It play structural role in heterochromatinheterochromatin formation. HP1 protein can have both activating as well repressive function in gene expression.

Heterochromatin protein 1 is well known conserved protein involved in heterochromatin formation and gene silencing .His tone methyl transferase enzyme methylated the histone H3 at lysine 9 creating selective binding site for itself.

30nm fiber is formed through the action of his tone 1 on nucleosome DNA in the 10nm fiber. Compaction of 10nm fiber to give 30nm is achieved by intera tion of H1 protein with both linker DNA and histone octamer.

Histone are octamer of eight protein comp!ex formed at the nucleosome core particle.