1ng9
From Proteopedia
(New page: 200px<br /><applet load="1ng9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ng9, resolution 2.60Å" /> '''E.coli MutS R697A: a...) |
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| - | [[Image:1ng9.gif|left|200px]]<br /><applet load="1ng9" size=" | + | [[Image:1ng9.gif|left|200px]]<br /><applet load="1ng9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ng9, resolution 2.60Å" /> | caption="1ng9, resolution 2.60Å" /> | ||
'''E.coli MutS R697A: an ATPase-asymmetry mutant'''<br /> | '''E.coli MutS R697A: an ATPase-asymmetry mutant'''<br /> | ||
==Overview== | ==Overview== | ||
| - | DNA mismatch repair is an essential safeguard of genomic integrity by | + | DNA mismatch repair is an essential safeguard of genomic integrity by removing base mispairings that may arise from DNA polymerase errors or from homologous recombination between DNA strands. In Escherichia coli, the MutS enzyme recognizes mismatches and initiates repair. MutS has an intrinsic ATPase activity crucial for its function, but which is poorly understood. We show here that within the MutS homodimer, the two chemically identical ATPase sites have different affinities for ADP, and the two sites alternate in ATP hydrolysis. A single residue, Arg697, located at the interface of the two ATPase domains, controls the asymmetry. When mutated, the asymmetry is lost and mismatch repair in vivo is impaired. We propose that asymmetry of the ATPase domains is an essential feature of mismatch repair that controls the timing of the different steps in the repair cascade. |
==About this Structure== | ==About this Structure== | ||
| - | 1NG9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with MG and ADP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1NG9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=ADP:'>ADP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NG9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Lamers, M | + | [[Category: Lamers, M H.]] |
| - | [[Category: Sixma, T | + | [[Category: Sixma, T K.]] |
| - | [[Category: Winterwerp, H | + | [[Category: Winterwerp, H H.K.]] |
[[Category: ADP]] | [[Category: ADP]] | ||
[[Category: MG]] | [[Category: MG]] | ||
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[[Category: dna repair]] | [[Category: dna repair]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:05:43 2008'' |
Revision as of 12:05, 21 February 2008
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E.coli MutS R697A: an ATPase-asymmetry mutant
Overview
DNA mismatch repair is an essential safeguard of genomic integrity by removing base mispairings that may arise from DNA polymerase errors or from homologous recombination between DNA strands. In Escherichia coli, the MutS enzyme recognizes mismatches and initiates repair. MutS has an intrinsic ATPase activity crucial for its function, but which is poorly understood. We show here that within the MutS homodimer, the two chemically identical ATPase sites have different affinities for ADP, and the two sites alternate in ATP hydrolysis. A single residue, Arg697, located at the interface of the two ATPase domains, controls the asymmetry. When mutated, the asymmetry is lost and mismatch repair in vivo is impaired. We propose that asymmetry of the ATPase domains is an essential feature of mismatch repair that controls the timing of the different steps in the repair cascade.
About this Structure
1NG9 is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.
Reference
The alternating ATPase domains of MutS control DNA mismatch repair., Lamers MH, Winterwerp HH, Sixma TK, EMBO J. 2003 Feb 3;22(3):746-56. PMID:12554674
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