2qjm
From Proteopedia
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| - | [[Image:2qjm.gif|left|200px]] | + | [[Image:2qjm.gif|left|200px]] |
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| - | '''Crystal structure of the K271E mutant of Mannonate dehydratase from Novosphingobium aromaticivorans complexed with Mg and D-mannonate''' | + | {{Structure |
| + | |PDB= 2qjm |SIZE=350|CAPTION= <scene name='initialview01'>2qjm</scene>, resolution 2.20Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <scene name='pdbligand=CS2:D-MANNONIC ACID'>CS2</scene> | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''Crystal structure of the K271E mutant of Mannonate dehydratase from Novosphingobium aromaticivorans complexed with Mg and D-mannonate''' | ||
| + | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2QJM is a [ | + | 2QJM is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Novosphingobium_aromaticivorans Novosphingobium aromaticivorans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QJM OCA]. |
==Reference== | ==Reference== | ||
| - | Evolution of enzymatic activities in the enolase superfamily: D-Mannonate dehydratase from Novosphingobium aromaticivorans., Rakus JF, Fedorov AA, Fedorov EV, Glasner ME, Vick JE, Babbitt PC, Almo SC, Gerlt JA, Biochemistry. 2007 Nov 13;46(45):12896-908. Epub 2007 Oct 18. PMID:[http:// | + | Evolution of enzymatic activities in the enolase superfamily: D-Mannonate dehydratase from Novosphingobium aromaticivorans., Rakus JF, Fedorov AA, Fedorov EV, Glasner ME, Vick JE, Babbitt PC, Almo SC, Gerlt JA, Biochemistry. 2007 Nov 13;46(45):12896-908. Epub 2007 Oct 18. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17944491 17944491] |
[[Category: Novosphingobium aromaticivorans]] | [[Category: Novosphingobium aromaticivorans]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: lyase]] | [[Category: lyase]] | ||
| - | ''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 18:26:30 2008'' |
Revision as of 16:26, 20 March 2008
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| , resolution 2.20Å | |||||||
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| Ligands: | and | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of the K271E mutant of Mannonate dehydratase from Novosphingobium aromaticivorans complexed with Mg and D-mannonate
Overview
The d-mannonate dehydratase (ManD) function was assigned to a group of orthologous proteins in the mechanistically diverse enolase superfamily by screening a library of acid sugars. Structures of the wild type ManD from Novosphingobium aromaticivorans were determined at pH 7.5 in the presence of Mg2+ and also in the presence of Mg2+ and the 2-keto-3-keto-d-gluconate dehydration product; the structure of the catalytically active K271E mutant was determined at pH 5.5 in the presence of the d-mannonate substrate. As previously observed in the structures of other members of the enolase superfamily, ManD contains two domains, an N-terminal alpha+beta capping domain and a (beta/alpha)7beta-barrel domain. The barrel domain contains the ligands for the essential Mg2+, Asp 210, Glu 236, and Glu 262, at the ends of the third, fourth, and fifth beta-strands of the barrel domain, respectively. However, the barrel domain lacks both the Lys acid/base catalyst at the end of the second beta-strand and the His-Asp dyad acid/base catalyst at the ends of the seventh and sixth beta-strands, respectively, that are found in many members of the superfamily. Instead, a hydrogen-bonded dyad of Tyr 159 in a loop following the second beta-strand and Arg 147 at the end of the second beta-strand are positioned to initiate the reaction by abstraction of the 2-proton. Both Tyr 159 and His 212, at the end of the third beta-strand, are positioned to facilitate both syn-dehydration and ketonization of the resulting enol intermediate to yield the 2-keto-3-keto-d-gluconate product with the observed retention of configuration. The identities and locations of these acid/base catalysts as well as of cationic amino acid residues that stabilize the enolate anion intermediate define a new structural strategy for catalysis (subgroup) in the mechanistically diverse enolase superfamily. With these differences, we provide additional evidence that the ligands for the essential Mg2+ are the only conserved residues in the enolase superfamily, establishing the primary functional importance of the Mg2+-assisted strategy for stabilizing the enolate anion intermediate.
About this Structure
2QJM is a Single protein structure of sequence from Novosphingobium aromaticivorans. Full crystallographic information is available from OCA.
Reference
Evolution of enzymatic activities in the enolase superfamily: D-Mannonate dehydratase from Novosphingobium aromaticivorans., Rakus JF, Fedorov AA, Fedorov EV, Glasner ME, Vick JE, Babbitt PC, Almo SC, Gerlt JA, Biochemistry. 2007 Nov 13;46(45):12896-908. Epub 2007 Oct 18. PMID:17944491
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