1s3c
From Proteopedia
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| - | [[Image:1s3c.gif|left|200px]] | + | [[Image:1s3c.gif|left|200px]] |
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| - | '''ARSENATE REDUCTASE C12S MUTANT FROM E. COLI''' | + | {{Structure |
| + | |PDB= 1s3c |SIZE=350|CAPTION= <scene name='initialview01'>1s3c</scene>, resolution 1.25Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> and <scene name='pdbligand=CS:CESIUM ION'>CS</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Arsenate_reductase_(glutaredoxin) Arsenate reductase (glutaredoxin)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.20.4.1 1.20.4.1] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''ARSENATE REDUCTASE C12S MUTANT FROM E. COLI''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1S3C is a [ | + | 1S3C is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S3C OCA]. |
==Reference== | ==Reference== | ||
| - | Arginine 60 in the ArsC arsenate reductase of E. coli plasmid R773 determines the chemical nature of the bound As(III) product., DeMel S, Shi J, Martin P, Rosen BP, Edwards BF, Protein Sci. 2004 Sep;13(9):2330-40. Epub 2004 Aug 4. PMID:[http:// | + | Arginine 60 in the ArsC arsenate reductase of E. coli plasmid R773 determines the chemical nature of the bound As(III) product., DeMel S, Shi J, Martin P, Rosen BP, Edwards BF, Protein Sci. 2004 Sep;13(9):2330-40. Epub 2004 Aug 4. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15295115 15295115] |
[[Category: Arsenate reductase (glutaredoxin)]] | [[Category: Arsenate reductase (glutaredoxin)]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
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[[Category: reductase]] | [[Category: reductase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 13:59:52 2008'' |
Revision as of 11:59, 20 March 2008
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| , resolution 1.25Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | Arsenate reductase (glutaredoxin), with EC number 1.20.4.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ARSENATE REDUCTASE C12S MUTANT FROM E. COLI
Overview
Arsenic is a ubiquitous environmental toxic metal. Consequently, organisms detoxify arsenate by reduction to arsenite, which is then excreted or sequestered. The ArsC arsenate reductase from Escherichia coli plasmid R773, the best characterized arsenic-modifying enzyme, has a catalytic cysteine, Cys 12, in the active site, surrounded by an arginine triad composed of Arg 60, Arg 94, and Arg 107. During the reaction cycle, the native enzyme forms a unique monohydroxyl Cys 12-thiol-arsenite adduct that contains a positive charge on the arsenic. We hypothesized previously that this unstable intermediate allows for rapid dissociation of the product arsenite. In this study, the role of Arg 60 in product formation was evaluated by mutagenesis. A total of eight new structures of ArsC were determined at resolutions between 1.3 A and 1.8 A, with R(free) values between 0.18 and 0.25. The crystal structures of R60K and R60A ArsC equilibrated with the product arsenite revealed a covalently bound Cys 12-thiol-dihydroxyarsenite without a charge on the arsenic atom. We propose that this intermediate is more stable than the monohydroxyarsenite intermediate of the native enzyme, resulting in slow release of product and, consequently, loss of activity.
About this Structure
1S3C is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Arginine 60 in the ArsC arsenate reductase of E. coli plasmid R773 determines the chemical nature of the bound As(III) product., DeMel S, Shi J, Martin P, Rosen BP, Edwards BF, Protein Sci. 2004 Sep;13(9):2330-40. Epub 2004 Aug 4. PMID:15295115
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