1gef: Difference between revisions
New page: left|200px<br /><applet load="1gef" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gef, resolution 2.0Å" /> '''CRYSTAL STRUCTURE OF ... |
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[[Image:1gef.gif|left|200px]]<br /><applet load="1gef" size=" | [[Image:1gef.gif|left|200px]]<br /><applet load="1gef" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1gef, resolution 2.0Å" /> | caption="1gef, resolution 2.0Å" /> | ||
'''CRYSTAL STRUCTURE OF THE ARCHAEAL HOLLIDAY JUNCTION RESOLVASE HJC'''<br /> | '''CRYSTAL STRUCTURE OF THE ARCHAEAL HOLLIDAY JUNCTION RESOLVASE HJC'''<br /> | ||
==Overview== | ==Overview== | ||
BACKGROUND: Homologous recombination is a crucial mechanism in determining | BACKGROUND: Homologous recombination is a crucial mechanism in determining genetic diversity and repairing damaged chromosomes. Holliday junction is the universal DNA intermediate whose interaction with proteins is one of the major events in the recombinational process. Hjc is an archaeal endonuclease, which specifically resolves the junction DNA to produce two separate recombinant DNA duplexes. The atomic structure of Hjc should clarify the mechanisms of the specific recognition with Holliday junction and the catalytic reaction. RESULTS: The crystal structure of Hjc from the hyperthermophilic archaeon Pyrococcus furiosus has been determined at 2.0 A resolution. The active Hjc molecule forms a homodimer, where an extensive hydrophobic interface tightly assembles two subunits of a single compact domain. The folding of the Hjc subunit is clearly different from any other Holliday junction resolvases thus far known. Instead, it resembles those of type II restriction endonucleases, including the configurations of the active site residues, which constitute the canonical catalytic motifs. The dimeric Hjc molecule displays an extensive basic surface on one side, which contains many conserved amino acids, including those in the active site. CONCLUSIONS: The architectural similarity of Hjc to restriction endonucleases allowed us to construct a putative model of the complex with Holliday junction. This model accounts for how Hjc recognizes and resolves the junction DNA in a specific manner. Mutational and biochemical analyses highlight the importance of some loops and the amino terminal region in interaction with DNA. | ||
==About this Structure== | ==About this Structure== | ||
1GEF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1GEF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GEF OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: holliday junction resolvase]] | [[Category: holliday junction resolvase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:49:09 2008'' | ||
Revision as of 13:49, 21 February 2008
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CRYSTAL STRUCTURE OF THE ARCHAEAL HOLLIDAY JUNCTION RESOLVASE HJC
OverviewOverview
BACKGROUND: Homologous recombination is a crucial mechanism in determining genetic diversity and repairing damaged chromosomes. Holliday junction is the universal DNA intermediate whose interaction with proteins is one of the major events in the recombinational process. Hjc is an archaeal endonuclease, which specifically resolves the junction DNA to produce two separate recombinant DNA duplexes. The atomic structure of Hjc should clarify the mechanisms of the specific recognition with Holliday junction and the catalytic reaction. RESULTS: The crystal structure of Hjc from the hyperthermophilic archaeon Pyrococcus furiosus has been determined at 2.0 A resolution. The active Hjc molecule forms a homodimer, where an extensive hydrophobic interface tightly assembles two subunits of a single compact domain. The folding of the Hjc subunit is clearly different from any other Holliday junction resolvases thus far known. Instead, it resembles those of type II restriction endonucleases, including the configurations of the active site residues, which constitute the canonical catalytic motifs. The dimeric Hjc molecule displays an extensive basic surface on one side, which contains many conserved amino acids, including those in the active site. CONCLUSIONS: The architectural similarity of Hjc to restriction endonucleases allowed us to construct a putative model of the complex with Holliday junction. This model accounts for how Hjc recognizes and resolves the junction DNA in a specific manner. Mutational and biochemical analyses highlight the importance of some loops and the amino terminal region in interaction with DNA.
About this StructureAbout this Structure
1GEF is a Single protein structure of sequence from Pyrococcus furiosus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the archaeal holliday junction resolvase Hjc and implications for DNA recognition., Nishino T, Komori K, Tsuchiya D, Ishino Y, Morikawa K, Structure. 2001 Mar 7;9(3):197-204. PMID:11286886
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