1xoa: Difference between revisions

Revision as of 15:17, 3 May 2008

THIOREDOXIN (OXIDIZED DISULFIDE FORM), NMR, 20 STRUCTURES

OverviewOverview

BACKGROUND: Thioredoxin participates in thiol-disulfide exchange reactions and both oxidized thioredoxin (disulfide form) and reduced thioredoxin (dithiol form) are found under physiological conditions. Previous structural studies suggested that the two forms were extremely similar, although significant functional and spectroscopic differences exist. We therefore undertook high-resolution solution structural studies of the two forms of Escherichia coli thioredoxin in order to detect subtle conformational differences. RESULTS: The solution structures of reduced and oxidized thioredoxin are extremely similar. Backbone structure is largely identical in the two forms, with slight differences in the region of the active site, which includes Cys32 and Cys35. The side chain sulfur atom of Cys32 is tilted away from that of Cys35 in the reduced form of the protein to accommodate the increase in S-S distance that occurs upon reduction of the disulfide, but the chi 1 angles of the two cysteines remain the same in the two forms. CONCLUSIONS: Only subtle conformational changes occur upon changing the oxidation state of the active site cysteines, including the positions of some side chains and in hydrogen bonding patterns in the active site region. Functional differences between the two forms are probably therefore related to differences in local conformational flexibility in and near the active site loop.

About this StructureAbout this Structure

1XOA is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

High-resolution solution structures of oxidized and reduced Escherichia coli thioredoxin., Jeng MF, Campbell AP, Begley T, Holmgren A, Case DA, Wright PE, Dyson HJ, Structure. 1994 Sep 15;2(9):853-68. PMID:7812718 Page seeded by OCA on Sat May 3 15:17:34 2008

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OCA

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 [[Image:1xoa.jpg|left|200px]]
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 '''THIOREDOXIN (OXIDIZED DISULFIDE FORM), NMR, 20 STRUCTURES'''
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 [[Category: Jeng, M F.]]
 [[Category: Wright, P E.]]
-[[Category: electron transport]]
+[[Category: Electron transport]]
-[[Category: redox-active center]]
+[[Category: Redox-active center]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 15:17:34 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:52:21 2008''