1wvb
From Proteopedia
(New page: 200px<br /> <applet load="1wvb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1wvb, resolution 2.30Å" /> '''Crystal structure o...) |
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| - | [[Image:1wvb.gif|left|200px]]<br /> | + | [[Image:1wvb.gif|left|200px]]<br /><applet load="1wvb" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1wvb" size=" | + | |
caption="1wvb, resolution 2.30Å" /> | caption="1wvb, resolution 2.30Å" /> | ||
'''Crystal structure of human arginase I: the mutant E256Q'''<br /> | '''Crystal structure of human arginase I: the mutant E256Q'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of the trimeric, manganese metalloenzyme, rat liver | + | The structure of the trimeric, manganese metalloenzyme, rat liver arginase, has been previously determined at 2.1-A resolution (Kanyo, Z. F., Scolnick, L. R., Ash, D. E., and Christianson, D. W., (1996) Nature 383, 554-557). A key feature of this structure is a novel S-shaped oligomerization motif at the carboxyl terminus of the protein that mediates approximately 54% of the intermonomer contacts. Arg-308, located within this oligomerization motif, nucleates a series of intramonomer and intermonomer salt links. In contrast to the trimeric wild-type enzyme, the R308A, R308E, and R308K variants of arginase exist as monomeric species, as determined by gel filtration and analytical ultracentrifugation, indicating that mutation of Arg-308 shifts the equilibrium for trimer dissociation by at least a factor of 10(5). These monomeric arginase variants are catalytically active, with k(cat)/K(m) values that are 13-17% of the value for wild-type enzyme. The arginase variants are characterized by decreased temperature stability relative to the wild-type enzyme. Differential scanning calorimetry shows that the midpoint temperature for unfolding of the Arg-308 variants is in the range of 63.6-65.5 degrees C, while the corresponding value for the wild-type enzyme is 70 degrees C. The three-dimensional structure of the R308K variant has been determined at 3-A resolution. At the high protein concentrations utilized in the crystallizations, this variant exists as a trimer, but weakened salt link interactions are observed for Lys-308. |
==About this Structure== | ==About this Structure== | ||
| - | 1WVB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with MN and S2C as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Arginase Arginase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.3.1 3.5.3.1] Full crystallographic information is available from [http:// | + | 1WVB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=MN:'>MN</scene> and <scene name='pdbligand=S2C:'>S2C</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Arginase Arginase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.3.1 3.5.3.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WVB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Centeno, F.]] | [[Category: Centeno, F.]] | ||
| - | [[Category: Christianson, D | + | [[Category: Christianson, D W.]] |
| - | [[Category: Costanzo, L | + | [[Category: Costanzo, L Di.]] |
[[Category: Guadalupe, S.]] | [[Category: Guadalupe, S.]] | ||
[[Category: Mora, A.]] | [[Category: Mora, A.]] | ||
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[[Category: twinned crystal]] | [[Category: twinned crystal]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:48:27 2008'' |
Revision as of 13:48, 21 February 2008
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Crystal structure of human arginase I: the mutant E256Q
Overview
The structure of the trimeric, manganese metalloenzyme, rat liver arginase, has been previously determined at 2.1-A resolution (Kanyo, Z. F., Scolnick, L. R., Ash, D. E., and Christianson, D. W., (1996) Nature 383, 554-557). A key feature of this structure is a novel S-shaped oligomerization motif at the carboxyl terminus of the protein that mediates approximately 54% of the intermonomer contacts. Arg-308, located within this oligomerization motif, nucleates a series of intramonomer and intermonomer salt links. In contrast to the trimeric wild-type enzyme, the R308A, R308E, and R308K variants of arginase exist as monomeric species, as determined by gel filtration and analytical ultracentrifugation, indicating that mutation of Arg-308 shifts the equilibrium for trimer dissociation by at least a factor of 10(5). These monomeric arginase variants are catalytically active, with k(cat)/K(m) values that are 13-17% of the value for wild-type enzyme. The arginase variants are characterized by decreased temperature stability relative to the wild-type enzyme. Differential scanning calorimetry shows that the midpoint temperature for unfolding of the Arg-308 variants is in the range of 63.6-65.5 degrees C, while the corresponding value for the wild-type enzyme is 70 degrees C. The three-dimensional structure of the R308K variant has been determined at 3-A resolution. At the high protein concentrations utilized in the crystallizations, this variant exists as a trimer, but weakened salt link interactions are observed for Lys-308.
About this Structure
1WVB is a Single protein structure of sequence from Homo sapiens with and as ligands. Active as Arginase, with EC number 3.5.3.1 Full crystallographic information is available from OCA.
Reference
Subunit-subunit interactions in trimeric arginase. Generation of active monomers by mutation of a single amino acid., Lavulo LT, Sossong TM Jr, Brigham-Burke MR, Doyle ML, Cox JD, Christianson DW, Ash DE, J Biol Chem. 2001 Apr 27;276(17):14242-8. Epub 2001 Jan 24. PMID:11278703
Page seeded by OCA on Thu Feb 21 15:48:27 2008
Categories: Arginase | Homo sapiens | Single protein | Centeno, F. | Christianson, D W. | Costanzo, L Di. | Guadalupe, S. | Mora, A. | MN | S2C | Hydrolase | Mutant e256q | Twinned crystal
