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1wvb
From Proteopedia
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{{STRUCTURE_1wvb| PDB=1wvb | SCENE= }} | {{STRUCTURE_1wvb| PDB=1wvb | SCENE= }} | ||
| - | + | ===Crystal structure of human arginase I: the mutant E256Q=== | |
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| - | ==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== | ==About this Structure== | ||
| - | 1WVB is a | + | 1WVB is a 2 chains structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WVB OCA]. |
==Reference== | ==Reference== | ||
| - | + | <ref group="xtra">PMID:11278703</ref><references group="xtra"/> | |
[[Category: Arginase]] | [[Category: Arginase]] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
| - | [[Category: Single protein]] | ||
[[Category: Centeno, F.]] | [[Category: Centeno, F.]] | ||
[[Category: Christianson, D W.]] | [[Category: Christianson, D W.]] | ||
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[[Category: Mutant e256q]] | [[Category: Mutant e256q]] | ||
[[Category: Twinned crystal]] | [[Category: Twinned crystal]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
| + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Feb 17 12:10:56 2009'' | ||
Revision as of 10:10, 17 February 2009
Crystal structure of human arginase I: the mutant E256Q
About this Structure
1WVB is a 2 chains structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
- Lavulo LT, Sossong TM Jr, Brigham-Burke MR, Doyle ML, Cox JD, Christianson DW, Ash DE. Subunit-subunit interactions in trimeric arginase. Generation of active monomers by mutation of a single amino acid. J Biol Chem. 2001 Apr 27;276(17):14242-8. Epub 2001 Jan 24. PMID:11278703 doi:10.1074/jbc.M010575200
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