1aaz
From Proteopedia
(New page: 200px<br /><applet load="1aaz" size="450" color="white" frame="true" align="right" spinBox="true" caption="1aaz, resolution 2.0Å" /> '''THE STRUCTURE OF OXID...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1aaz.gif|left|200px]]<br /><applet load="1aaz" size=" | + | [[Image:1aaz.gif|left|200px]]<br /><applet load="1aaz" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1aaz, resolution 2.0Å" /> | caption="1aaz, resolution 2.0Å" /> | ||
'''THE STRUCTURE OF OXIDIZED BACTERIOPHAGE T4 GLUTAREDOXIN (THIOREDOXIN)'''<br /> | '''THE STRUCTURE OF OXIDIZED BACTERIOPHAGE T4 GLUTAREDOXIN (THIOREDOXIN)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of wild-type bacteriophage T4 glutaredoxin (earlier called | + | The structure of wild-type bacteriophage T4 glutaredoxin (earlier called thioredoxin) in its oxidized form has been refined in a monoclinic crystal form at 2.0 A resolution to a crystallographic R-factor of 0.209. A mutant T4 glutaredoxin gives orthorhombic crystals of better quality. The structure of this mutant has been solved by molecular replacement methods and refined at 1.45 A to an R-value of 0.175. In this mutant glutaredoxin, the active site residues Val15 and Tyr16 have been substituted by Gly and Pro, respectively, to mimic that of Escherichia coli thioredoxin. The main-chain conformation of the wild-type protein is similar in the two independently determined molecules in the asymmetric unit of the monoclinic crystals. On the other hand, side-chain conformations differ considerably between the two molecules due to heterologous packing interactions in the crystals. The structure of the mutant protein is very similar to the wild-type protein, except at mutated positions and at parts involved in crystal contacts. The active site disulfide bridge between Cys14 and Cys17 is located at the first turn of helix alpha 1. The torsion angles of these residues are similar to those of Escherichia coli thioredoxin. The torsion angle around the S-S bond is smaller than that normally observed for disulfides: 58 degrees, 67 degrees and 67 degrees for wild-type glutaredoxin molecule A and B and mutant glutaredoxin, respectively. Each sulfur atom of the disulfide cysteines in T4 glutaredoxin forms a hydrogen bond to one main-chain nitrogen atom. The active site is shielded from solvent on one side by the beta-carbon atoms of the cysteine residues plus side-chains of residues 7, 9, 21 and 33. From the opposite side, there is a cleft where the sulfur atom of Cys14 is accessible and can be attacked by a nucleophilic thiolate ion in the initial step of the reduction reaction. |
==About this Structure== | ==About this Structure== | ||
| - | 1AAZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with CD as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1AAZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_t4 Bacteriophage t4] with <scene name='pdbligand=CD:'>CD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AAZ OCA]. |
==Reference== | ==Reference== | ||
| Line 19: | Line 19: | ||
[[Category: Nordlund, P.]] | [[Category: Nordlund, P.]] | ||
[[Category: Petratos, K.]] | [[Category: Petratos, K.]] | ||
| - | [[Category: Soderberg, B | + | [[Category: Soderberg, B O.]] |
[[Category: Sonnerstam, U.]] | [[Category: Sonnerstam, U.]] | ||
[[Category: Uhlin, T.]] | [[Category: Uhlin, T.]] | ||
| Line 25: | Line 25: | ||
[[Category: electron transport]] | [[Category: electron transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:42:45 2008'' |
Revision as of 09:42, 21 February 2008
|
THE STRUCTURE OF OXIDIZED BACTERIOPHAGE T4 GLUTAREDOXIN (THIOREDOXIN)
Overview
The structure of wild-type bacteriophage T4 glutaredoxin (earlier called thioredoxin) in its oxidized form has been refined in a monoclinic crystal form at 2.0 A resolution to a crystallographic R-factor of 0.209. A mutant T4 glutaredoxin gives orthorhombic crystals of better quality. The structure of this mutant has been solved by molecular replacement methods and refined at 1.45 A to an R-value of 0.175. In this mutant glutaredoxin, the active site residues Val15 and Tyr16 have been substituted by Gly and Pro, respectively, to mimic that of Escherichia coli thioredoxin. The main-chain conformation of the wild-type protein is similar in the two independently determined molecules in the asymmetric unit of the monoclinic crystals. On the other hand, side-chain conformations differ considerably between the two molecules due to heterologous packing interactions in the crystals. The structure of the mutant protein is very similar to the wild-type protein, except at mutated positions and at parts involved in crystal contacts. The active site disulfide bridge between Cys14 and Cys17 is located at the first turn of helix alpha 1. The torsion angles of these residues are similar to those of Escherichia coli thioredoxin. The torsion angle around the S-S bond is smaller than that normally observed for disulfides: 58 degrees, 67 degrees and 67 degrees for wild-type glutaredoxin molecule A and B and mutant glutaredoxin, respectively. Each sulfur atom of the disulfide cysteines in T4 glutaredoxin forms a hydrogen bond to one main-chain nitrogen atom. The active site is shielded from solvent on one side by the beta-carbon atoms of the cysteine residues plus side-chains of residues 7, 9, 21 and 33. From the opposite side, there is a cleft where the sulfur atom of Cys14 is accessible and can be attacked by a nucleophilic thiolate ion in the initial step of the reduction reaction.
About this Structure
1AAZ is a Single protein structure of sequence from Bacteriophage t4 with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of oxidized bacteriophage T4 glutaredoxin (thioredoxin). Refinement of native and mutant proteins., Eklund H, Ingelman M, Soderberg BO, Uhlin T, Nordlund P, Nikkola M, Sonnerstam U, Joelson T, Petratos K, J Mol Biol. 1992 Nov 20;228(2):596-618. PMID:1453466
Page seeded by OCA on Thu Feb 21 11:42:45 2008
