2io5: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2io5.jpg|left|200px]] | [[Image:2io5.jpg|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_2io5", creates the "Structure Box" on the page. | |||
You may change the PDB parameter (which sets the PDB file loaded into the applet) | |||
or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |||
or leave the SCENE parameter empty for the default display. | |||
--> | |||
{{STRUCTURE_2io5| PDB=2io5 | SCENE= }} | |||
| | |||
| | |||
}} | |||
'''Crystal structure of the CIA- histone H3-H4 complex''' | '''Crystal structure of the CIA- histone H3-H4 complex''' | ||
| Line 30: | Line 27: | ||
[[Category: Natsume, R.]] | [[Category: Natsume, R.]] | ||
[[Category: Senda, T.]] | [[Category: Senda, T.]] | ||
[[Category: | [[Category: Chaperone]] | ||
[[Category: | [[Category: Histone]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 07:42:36 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 07:42, 4 May 2008
Crystal structure of the CIA- histone H3-H4 complex
OverviewOverview
CIA (CCG1-interacting factor A)/ASF1, which is the most conserved histone chaperone among the eukaryotes, was genetically identified as a factor for an anti-silencing function (Asf1) by yeast genetic screening. Shortly after that, the CIA-histone-H3-H4 complex was isolated from Drosophila as a histone chaperone CAF-1 stimulator. Human CIA-I/II (ASF1a/b) was identified as a histone chaperone that interacts with the bromodomain-an acetylated-histone-recognizing domain-of CCG1, in the general transcription initiation factor TFIID. Intensive studies have revealed that CIA/ASF1 mediates nucleosome assembly by forming a complex with another histone chaperone in human cells and yeast, and is involved in DNA replication, transcription, DNA repair and silencing/anti-silencing in yeast. CIA/ASF1 was shown as a major storage chaperone for soluble histones in proliferating human cells. Despite all these biochemical and biological functional analyses, the structure-function relationship of the nucleosome assembly/disassembly activity of CIA/ASF1 has remained elusive. Here we report the crystal structure, at 2.7 A resolution, of CIA-I in complex with histones H3 and H4. The structure shows the histone H3-H4 dimer's mutually exclusive interactions with another histone H3-H4 dimer and CIA-I. The carboxy-terminal beta-strand of histone H4 changes its partner from the beta-strand in histone H2A to that of CIA-I through large conformational change. In vitro functional analysis demonstrated that CIA-I has a histone H3-H4 tetramer-disrupting activity. Mutants with weak histone H3-H4 dimer binding activity showed critical functional effects on cellular processes related to transcription. The histone H3-H4 tetramer-disrupting activity of CIA/ASF1 and the crystal structure of the CIA/ASF1-histone-H3-H4 dimer complex should give insights into mechanisms of both nucleosome assembly/disassembly and nucleosome semi-conservative replication.
About this StructureAbout this Structure
2IO5 is a Protein complex structure of sequences from Homo sapiens and Xenopus laevis. Full crystallographic information is available from OCA.
ReferenceReference
Structure and function of the histone chaperone CIA/ASF1 complexed with histones H3 and H4., Natsume R, Eitoku M, Akai Y, Sano N, Horikoshi M, Senda T, Nature. 2007 Mar 15;446(7133):338-41. Epub 2007 Feb 11. PMID:17293877 Page seeded by OCA on Sun May 4 07:42:36 2008