Lec17 - Lecture 17 Eukaryotic Genome 2 Chromatin Structure...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 17 Eukaryotic Genome 2 - Chromatin Structure I Lodish.6th edition Chapter 6.6 p247-250 & 254-257
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sizes of various genomes
Background image of page 2
Human genomic DNA: about 1 meter long x 2N chromosomes = 2m Average length of DNA/human chromosome: about 4 cm (4x10 -2 m) Nucleus about 4x10 -6 m (4 μ m in diameter) DNA Compaction of about 10 4 - 10 5 fold: Ball 2cm (0.8 inch diameter) Fiber 10 μ m (0.01mm diameter) 10 km (6.25 miles long) High compaction of DNA in nucleus -> entangled ±bers ->Problem for DNA replication & Transcription Solution: genomic DNA is compacted and organized into a structure called Chromatin .
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Histones are highly conserved in all organisms. (Only 2 aa differences in H4 from pea to human) Chromatin: composed of DNA and Histone proteins (mostly) but also of Non-histone proteins (e.g. matrix/scaffold proteins, “high-mobility group” or “HMG” proteins, and other DNA-binding proteins) The nucleosome is the basic structural repeating unit of chromatin and is the first level of order in chromatin. The nucleosome is composed of DNA (160-200 bp), 2 copies each of 4 core histones, and one linker histone. Highly Basic. Linker histone Core histones (Da)
Background image of page 4
Tail sequences for the main human histone variants are shown with every tenth residue in bold type. The Frst (N-termini) or last (C-terminus of H2A) residues to be included in the molecular models from the crystal structures of the core histone octamer or a nucleosome core are indicated as A or L, respectively. L1 and L2 indicate cases where different numbers of residues for each of the two
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 05/26/2011.

Page1 / 24

Lec17 - Lecture 17 Eukaryotic Genome 2 Chromatin Structure...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online