Nucleosome structure
From Proteopedia
(Difference between revisions)
| Line 3: | Line 3: | ||
<Structure load='1aoi' size='800' frame='true' align='right' caption='Nucleosoma' scene='60/602771/Proteinas/5'/> | <Structure load='1aoi' size='800' frame='true' align='right' caption='Nucleosoma' scene='60/602771/Proteinas/5'/> | ||
<big><big>'''Nucleosome''' is the basic structure of '''chromatin fiber'''. A nucleosome consists of a core with a '''histonic proteins octamer''' and a '''DNA''' molecule 146 bp long wound around this core in two complete turns. | <big><big>'''Nucleosome''' is the basic structure of '''chromatin fiber'''. A nucleosome consists of a core with a '''histonic proteins octamer''' and a '''DNA''' molecule 146 bp long wound around this core in two complete turns. | ||
| - | + | Histonic protein octamer includes four types of proteins: <scene name='60/602771/Histonah2a/1'>H2A</scene>, <scene name='60/602771/Histonah2b/1'>H2B</scene>, <scene name='60/602771/Histonah3/1'>H3</scene> y <scene name='60/602771/Histonah4/1'>H4</scene>. Histonic proteins are organized in dimers so: | |
*Two H3-H4 dimers | *Two H3-H4 dimers | ||
| Line 17: | Line 17: | ||
The more widespread secondary structure in <scene name='60/602771/Octamero/2'>histonic proteins</scene> is <scene name='60/602771/Secondarystructure/1'>alfa helix</scene>. | The more widespread secondary structure in <scene name='60/602771/Octamero/2'>histonic proteins</scene> is <scene name='60/602771/Secondarystructure/1'>alfa helix</scene>. | ||
| - | + | ||
<small> | <small> | ||
== References == | == References == | ||
Revision as of 12:32, 9 February 2016
|
Nucleosome is the basic structure of chromatin fiber. A nucleosome consists of a core with a histonic proteins octamer and a DNA molecule 146 bp long wound around this core in two complete turns. Histonic protein octamer includes four types of proteins: , , y . Histonic proteins are organized in dimers so:
- Two H3-H4 dimers
- Two H2A-H2B dimers
- molecule wound in around octamer. Some complete the whole structure.
The more widespread secondary structure in is .
References
This page is based on 1aoi file from Proteopedia.
1aoi is a 10 chain structure with sequence from Xenopus laevis. The July 2000 RCSB PDB Molecule of the Month feature on Nucleosome by David S. Goodsell is 10.2210/rcsb_pdb/mom_2000_7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
