The conserved function of the replication components extends to the clamp loader and processivity clamp as well other functions of the replisome.

The roles of RFC and PCNA are analogous to the E. coli γ clamp loader and β2 processivity unit

TLS Online TPP Program

#Id: 446

#Unit 2. Cellular Organization

Linker DNA comprises the rest of the repeating unit. Its length varies from as little as 8 bp to as many as 114 bp per nucleosome.

TLS Online TPP Program

#Id: 447

#Unit 2. Cellular Organization

The predicted mass of the nucleosome is 262 kD.

TLS Online TPP Program

#Id: 448

#Unit 2. Cellular Organization

The nucleosome consists of approximately equal masses of DNA and histones (including H1).

TLS Online TPP Program

#Id: 449

#Unit 2. Cellular Organization

H32-H42 tetramer accounts for the diameter of the octamer. It forms the shape of a horseshoe.

TLS Online TPP Program

#Id: 450

#Unit 2. Cellular Organization

All four core histones show a similar type of structure in which three a-helices are connected by two loops. This highly conserved structure is called the histone fold.

TLS Online TPP Program

#Id: 451

#Unit 2. Cellular Organization

Nucleosomes that contain linker H1 histones are referred to as chromatosomes.