DNA: Structure I - WOU Homepageguralnl/311DNAIhist.pdf · Pearson Benjamin Cummings. ... DNA replication machinery Figure 28.25 ... DNA: Structure Author: Western Oregon University

DNA: Structure I

• Chromosomes• Chromatin• Histones

Chromosomes

Eukaryotic Chromosomes

• DNA and HistoneProteins

• packaging of DNA • nucleosomes

Chromatin Structure

Histones

• Composed of proteins • rich in lysine and

arginine• conserved

Structure of Nucleosomes

• H2a, H2b, H3, H4 octamer

• H1 linker

Histone H1

Replication of histones

Requires histone chaperone proteins

DNA structure II

• DNA• Composition of DNA • Evidence for genetic material • Structure • Implications of the structure

DNA & Nucleotides