1a2m: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1a2m.gif|left|200px]]<br /> | [[Image:1a2m.gif|left|200px]]<br /><applet load="1a2m" size="450" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1a2m" size="450" color="white" frame="true" align="right" spinBox="true" | |||
caption="1a2m, resolution 2.7Å" /> | caption="1a2m, resolution 2.7Å" /> | ||
'''OXIDIZED DSBA AT 2.7 ANGSTROMS RESOLUTION, CRYSTAL FORM III'''<br /> | '''OXIDIZED DSBA AT 2.7 ANGSTROMS RESOLUTION, CRYSTAL FORM III'''<br /> | ||
| Line 8: | Line 7: | ||
==About this Structure== | ==About this Structure== | ||
1A2M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. | 1A2M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Known structural/functional Sites: <scene name='pdbsite=ACA:The Active Site For Molecule A'>ACA</scene> and <scene name='pdbsite=ACB:The Active Site For Molecule B'>ACB</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1A2M OCA]. | ||
==Reference== | ==Reference== | ||
| Line 22: | Line 21: | ||
[[Category: redox-active center]] | [[Category: redox-active center]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Dec 18 14:07:29 2007'' | ||
Revision as of 14:57, 18 December 2007
|
OXIDIZED DSBA AT 2.7 ANGSTROMS RESOLUTION, CRYSTAL FORM III
OverviewOverview
BACKGROUND: The redox proteins that incorporate a thioredoxin fold have, diverse properties and functions. The bacterial protein-folding factor, DsbA is the most oxidizing of the thioredoxin family. DsbA catalyzes, disulfide-bond formation during the folding of secreted proteins. The, extremely oxidizing nature of DsbA has been proposed to result from either, domain motion or stabilizing active-site interactions in the reduced form., In the domain motion model, hinge bending between the two domains of DsbA, occurs as a result of redox-related conformational changes. RESULTS: We, have determined the crystal structures of reduced and oxidized DsbA in the, same crystal form and at the same pH (5.6). The crystal structure of a, lower pH form of oxidized DsbA has also been determined (pH 5.0). These, new crystal structures of DsbA, and the previously determined structure of, oxidized DsbA at pH 6.5, provide the foundation for analysis of structural, changes that occur upon reduction of the active-site disulfide bond., CONCLUSIONS: The structures of reduced and oxidized DsbA reveal that hinge, bending motions do occur between the two domains. These motions are, independent of redox state, however, and therefore do not contribute to, the energetic differences between the two redox states. Instead, the, observed domain motion is proposed to be a consequence of substrate, binding. Furthermore, DsbA's highly oxidizing nature is a result of, hydrogen bond, electrostatic and helix-dipole interactions that favour the, thiolate over the disulfide at the active site.
About this StructureAbout this Structure
1A2M is a Single protein structure of sequence from Escherichia coli. Known structural/functional Sites: and . Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of reduced and oxidized DsbA: investigation of domain motion and thiolate stabilization., Guddat LW, Bardwell JC, Martin JL, Structure. 1998 Jun 15;6(6):757-67. PMID:9655827
Page seeded by OCA on Tue Dec 18 14:07:29 2007