2io5: Difference between revisions

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[[Image:2io5.jpg|left|200px]]<br /><applet load="2io5" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:2io5.jpg|left|200px]]<br /><applet load="2io5" size="350" color="white" frame="true" align="right" spinBox="true"

caption="2io5, resolution 2.700Å" />

'''Crystal structure of the CIA- histone H3-H4 complex'''<br />

==Overview==

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.

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 Structure==

2IO5 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=2IO5 OCA].

2IO5 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IO5 OCA].

==Reference==

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 Feb 11;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17293877 17293877]

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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17293877 17293877]

[[Category: Homo sapiens]]

[[Category: Protein complex]]

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[[Category: histone]]

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@@ Line 1: / Line 1: @@
-[[Image:2io5.jpg|left|200px]]<br /><applet load="2io5" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2io5.jpg|left|200px]]<br /><applet load="2io5" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2io5, resolution 2.700&Aring;" />
 '''Crystal structure of the CIA- histone H3-H4 complex'''<br />
 ==Overview==
-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.
+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 Structure==
-IO5 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2IO5 OCA].
+IO5 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IO5 OCA].
 ==Reference==
-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 Feb 11;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17293877 17293877]
+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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17293877 17293877]
 [[Category: Homo sapiens]]
 [[Category: Protein complex]]
@@ Line 21: / Line 21: @@
 [[Category: histone]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 12:23:31 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:54:33 2008''