2tir: Difference between revisions
New page: left|200px<br /><applet load="2tir" size="450" color="white" frame="true" align="right" spinBox="true" caption="2tir, resolution 2.0Å" /> '''CRYSTAL STRUCTURE ANA... |
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[[Image:2tir.jpg|left|200px]]<br /><applet load="2tir" size=" | [[Image:2tir.jpg|left|200px]]<br /><applet load="2tir" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2tir, resolution 2.0Å" /> | caption="2tir, resolution 2.0Å" /> | ||
'''CRYSTAL STRUCTURE ANALYSIS OF A MUTANT ESCHERICHIA COLI THIOREDOXIN IN WHICH LYSINE 36 IS REPLACED BY GLUTAMIC ACID'''<br /> | '''CRYSTAL STRUCTURE ANALYSIS OF A MUTANT ESCHERICHIA COLI THIOREDOXIN IN WHICH LYSINE 36 IS REPLACED BY GLUTAMIC ACID'''<br /> | ||
==Overview== | ==Overview== | ||
The structure of a mutant Escherichia coli thioredoxin with a glutamic | The structure of a mutant Escherichia coli thioredoxin with a glutamic acid substituted for a conserved lysine at position 36 adjacent to the active site has been solved using molecular replacement and refined at 2.0-A resolution to a crystallographic residual of 19.9%. The mutant was crystallized in an orthorhombic space group with one molecule in the asymmetric unit. The structure of the mutant thioredoxin shows overall good agreement with the wild-type E. coli thioredoxin. The root-mean-square deviations for all C alpha s are 0.45 and 0.79 A between the mutant structure and the two molecules in the asymmetric unit of the wild-type crystals. Structural changes are seen in several residues in the active-site region preceding the disulfide. A reverse turn of residues 29-32 changes the conformation from a type I to a type II turn. This change may be related to the loss of a hydrogen bond from Lys-36 to the main-chain carbonyl of residue 30 due to the mutation. The C alpha atom of Trp-31 has moved 1.9 A and the indole ring no longer makes hydrogen bonds to the carboxyl group of Asp-61 but instead participates in a crystal contact. The structural differences seen in the mutant thioredoxin may be influenced by the crystal packing. The substituted Glu-36 makes extensive crystal contacts. The static fluorescence of this mutant thioredoxin has a different pH dependence than the wild type. | ||
==About this Structure== | ==About this Structure== | ||
2TIR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CU as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 2TIR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=CU:'>CU</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2TIR OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Eklund, H.]] | [[Category: Eklund, H.]] | ||
[[Category: Fuchs, J | [[Category: Fuchs, J A.]] | ||
[[Category: Gleason, F | [[Category: Gleason, F K.]] | ||
[[Category: Nikkola, M.]] | [[Category: Nikkola, M.]] | ||
[[Category: CU]] | [[Category: CU]] | ||
[[Category: electron transport]] | [[Category: electron transport]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:49:47 2008'' | ||
Revision as of 16:49, 21 February 2008
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CRYSTAL STRUCTURE ANALYSIS OF A MUTANT ESCHERICHIA COLI THIOREDOXIN IN WHICH LYSINE 36 IS REPLACED BY GLUTAMIC ACID
Overview
The structure of a mutant Escherichia coli thioredoxin with a glutamic acid substituted for a conserved lysine at position 36 adjacent to the active site has been solved using molecular replacement and refined at 2.0-A resolution to a crystallographic residual of 19.9%. The mutant was crystallized in an orthorhombic space group with one molecule in the asymmetric unit. The structure of the mutant thioredoxin shows overall good agreement with the wild-type E. coli thioredoxin. The root-mean-square deviations for all C alpha s are 0.45 and 0.79 A between the mutant structure and the two molecules in the asymmetric unit of the wild-type crystals. Structural changes are seen in several residues in the active-site region preceding the disulfide. A reverse turn of residues 29-32 changes the conformation from a type I to a type II turn. This change may be related to the loss of a hydrogen bond from Lys-36 to the main-chain carbonyl of residue 30 due to the mutation. The C alpha atom of Trp-31 has moved 1.9 A and the indole ring no longer makes hydrogen bonds to the carboxyl group of Asp-61 but instead participates in a crystal contact. The structural differences seen in the mutant thioredoxin may be influenced by the crystal packing. The substituted Glu-36 makes extensive crystal contacts. The static fluorescence of this mutant thioredoxin has a different pH dependence than the wild type.
About this Structure
2TIR is a Single protein structure of sequence from Escherichia coli with CU as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure analysis of a mutant Escherichia coli thioredoxin in which lysine 36 is replaced by glutamic acid., Nikkola M, Gleason FK, Fuchs JA, Eklund H, Biochemistry. 1993 May 18;32(19):5093-8. PMID:8098620
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