From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1s98.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1s98.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1s98| PDB=1s98 | SCENE= }} | | {{STRUCTURE_1s98| PDB=1s98 | SCENE= }} |
| | | | |
| - | '''E.coli IscA crystal structure to 2.3 A'''
| + | ===E.coli IscA crystal structure to 2.3 A=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | IscA, an 11 kDa member of the hesB family of proteins, binds iron and [2Fe-2S] clusters, and participates in the biosynthesis of iron-sulfur proteins. We report the crystal structure of the apo-protein form of IscA from Escherichia coli to a resolution of 2.3A. The crystals belong to the space group P3(2)21 and have unit cell dimensions a=b=66.104 A, c=150.167 A (alpha=beta=90 degrees, gamma=120 degrees ). The structure was solved using single-wavelength anomalous dispersion (SAD) phasing of a selenomethionyl derivative, and the IscA model was refined to R=21.4% (Rfree=25.4%). IscA exists as an (alpha1alpha2)2 homotetramer with the (alpha1alpha2) dimer comprising the asymmetric unit. Cys35, implicated in Fe-S cluster assembly, is located in a central cavity formed at the tetramer interface with the gamma-sulfur atoms of residues from the alpha1 and alpha2' monomers (and alpha1'alpha2) positioned close to one another (approximately equal 7 A). C-terminal residues 99-107 are disordered, and the exact positions of Cys99 and Cys101 could not be determined. However, computer modeling of C-terminal residues in the tetramer suggests that Cys99 and Cys101 in the alpha1 monomer and those of the alpha1' monomer (or alpha2 and alpha2') are positioned sufficiently close to coordinate [2Fe-2S] clusters between the two dimers, whereas this is not possible within the (alpha1alpha2) or (alpha1'alpha2') dimer. This symmetrical arrangement allows for binding of two [2Fe-2S] clusters on opposite sides of the tetramer. Modeling further reveals that Cys101 is positioned sufficiently close to Cys35 to allow Cys35 to participate in cluster assembly, formation, or transfer.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_15050828}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 15050828 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_15050828}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 31: |
Line 35: |
| | [[Category: Isca]] | | [[Category: Isca]] |
| | [[Category: Sulfur]] | | [[Category: Sulfur]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 08:26:20 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 08:05:43 2008'' |
Revision as of 05:05, 29 July 2008
Template:STRUCTURE 1s98
E.coli IscA crystal structure to 2.3 A
Template:ABSTRACT PUBMED 15050828
About this Structure
1S98 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structure of IscA, an iron-sulfur cluster assembly protein from Escherichia coli., Cupp-Vickery JR, Silberg JJ, Ta DT, Vickery LE, J Mol Biol. 2004 Apr 16;338(1):127-37. PMID:15050828
Page seeded by OCA on Tue Jul 29 08:05:43 2008
