1huv
From Proteopedia
(New page: 200px<br /><applet load="1huv" size="450" color="white" frame="true" align="right" spinBox="true" caption="1huv, resolution 2.15Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1huv.jpg|left|200px]]<br /><applet load="1huv" size=" | + | [[Image:1huv.jpg|left|200px]]<br /><applet load="1huv" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1huv, resolution 2.15Å" /> | caption="1huv, resolution 2.15Å" /> | ||
'''CRYSTAL STRUCTURE OF A SOLUBLE MUTANT OF THE MEMBRANE-ASSOCIATED (S)-MANDELATE DEHYDROGENASE FROM PSEUDOMONAS PUTIDA AT 2.15A RESOLUTION'''<br /> | '''CRYSTAL STRUCTURE OF A SOLUBLE MUTANT OF THE MEMBRANE-ASSOCIATED (S)-MANDELATE DEHYDROGENASE FROM PSEUDOMONAS PUTIDA AT 2.15A RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of an active mutant of (S)-mandelate dehydrogenase | + | The structure of an active mutant of (S)-mandelate dehydrogenase (MDH-GOX2) from Pseudomonas putida has been determined at 2.15 A resolution. The membrane-associated flavoenzyme (S)-mandelate dehydrogenase (MDH) catalyzes the oxidation of (S)-mandelate to give a flavin hydroquinone intermediate which is subsequently reoxidized by an organic oxidant residing in the membrane. The enzyme was rendered soluble by replacing its 39-residue membrane-binding peptide segment with a corresponding 20-residue segment from its soluble homologue, glycolate oxidase (GOX). Because of their amphipathic nature and peculiar solubilization properties, membrane proteins are notoriously difficult to crystallize, yet represent a large fraction of the proteins encoded by genomes currently being deciphered. Here we present the first report of such a structure in which an internal membrane-binding segment has been replaced, leading to successful crystallization of the fully active enzyme in the absence of detergents. This approach may have general application to other membrane-bound proteins. The overall fold of the molecule is that of a TIM barrel, and it forms a tight tetramer within the crystal lattice that has circular 4-fold symmetry. The structure of MDH-GOX2 reveals how this molecule can interact with a membrane, although it is limited by the absence of a membrane-binding segment. MDH-GOX2 and GOX adopt similar conformations, yet they retain features characteristic of membrane and globular proteins, respectively. MDH-GOX2 has a distinctly electropositive surface capable of interacting with the membrane, while the opposite surface is largely electronegative. GOX shows no such pattern. MDH appears to form a new class of monotopic integral membrane protein that interacts with the membrane through coplanar electrostatic binding surfaces and hydrophobic interactions, thus combining features of both the prostaglandin synthase/squaline-hopine cyclase and the C-2 coagulation factor domain classes of membrane proteins. |
==About this Structure== | ==About this Structure== | ||
| - | 1HUV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida] with SO4, FMN and MES as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1HUV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=FMN:'>FMN</scene> and <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HUV OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pseudomonas putida]] | [[Category: Pseudomonas putida]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Mathews, F | + | [[Category: Mathews, F S.]] |
[[Category: Sukumar, N.]] | [[Category: Sukumar, N.]] | ||
[[Category: FMN]] | [[Category: FMN]] | ||
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[[Category: tim barrel]] | [[Category: tim barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:05:06 2008'' |
Revision as of 11:05, 21 February 2008
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CRYSTAL STRUCTURE OF A SOLUBLE MUTANT OF THE MEMBRANE-ASSOCIATED (S)-MANDELATE DEHYDROGENASE FROM PSEUDOMONAS PUTIDA AT 2.15A RESOLUTION
Overview
The structure of an active mutant of (S)-mandelate dehydrogenase (MDH-GOX2) from Pseudomonas putida has been determined at 2.15 A resolution. The membrane-associated flavoenzyme (S)-mandelate dehydrogenase (MDH) catalyzes the oxidation of (S)-mandelate to give a flavin hydroquinone intermediate which is subsequently reoxidized by an organic oxidant residing in the membrane. The enzyme was rendered soluble by replacing its 39-residue membrane-binding peptide segment with a corresponding 20-residue segment from its soluble homologue, glycolate oxidase (GOX). Because of their amphipathic nature and peculiar solubilization properties, membrane proteins are notoriously difficult to crystallize, yet represent a large fraction of the proteins encoded by genomes currently being deciphered. Here we present the first report of such a structure in which an internal membrane-binding segment has been replaced, leading to successful crystallization of the fully active enzyme in the absence of detergents. This approach may have general application to other membrane-bound proteins. The overall fold of the molecule is that of a TIM barrel, and it forms a tight tetramer within the crystal lattice that has circular 4-fold symmetry. The structure of MDH-GOX2 reveals how this molecule can interact with a membrane, although it is limited by the absence of a membrane-binding segment. MDH-GOX2 and GOX adopt similar conformations, yet they retain features characteristic of membrane and globular proteins, respectively. MDH-GOX2 has a distinctly electropositive surface capable of interacting with the membrane, while the opposite surface is largely electronegative. GOX shows no such pattern. MDH appears to form a new class of monotopic integral membrane protein that interacts with the membrane through coplanar electrostatic binding surfaces and hydrophobic interactions, thus combining features of both the prostaglandin synthase/squaline-hopine cyclase and the C-2 coagulation factor domain classes of membrane proteins.
About this Structure
1HUV is a Single protein structure of sequence from Pseudomonas putida with , and as ligands. Full crystallographic information is available from OCA.
Reference
Structure of an active soluble mutant of the membrane-associated (S)-mandelate dehydrogenase., Sukumar N, Xu Y, Gatti DL, Mitra B, Mathews FS, Biochemistry. 2001 Aug 21;40(33):9870-8. PMID:11502180
Page seeded by OCA on Thu Feb 21 13:05:06 2008
Categories: Pseudomonas putida | Single protein | Mathews, F S. | Sukumar, N. | FMN | MES | SO4 | Tim barrel
