1r4q: Difference between revisions
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|SITE= | |SITE= | ||
|LIGAND= | |LIGAND= | ||
|ACTIVITY= [http://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] </span> | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1r4p|1R4P]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1r4q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1r4q OCA], [http://www.ebi.ac.uk/pdbsum/1r4q PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1r4q RCSB]</span> | |||
}} | }} | ||
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[[Category: ab5 toxin]] | [[Category: ab5 toxin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:23:12 2008'' | ||
Revision as of 23:23, 30 March 2008
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| , resolution 2.50Å | |||||||
|---|---|---|---|---|---|---|---|
| Activity: | rRNA N-glycosylase, with EC number 3.2.2.22 | ||||||
| Related: | 1R4P
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Shiga toxin
OverviewOverview
Several serotypes of Escherichia coli produce protein toxins closely related to Shiga toxin (Stx) from Shigella dysenteriae serotype 1. These Stx-producing E. coli cause outbreaks of hemorrhagic colitis and hemolytic uremic syndrome in humans, with the latter being more likely if the E. coli produce Stx2 than if they only produce Stx1. To investigate the differences among the Stxs, which are all AB(5) toxins, the crystal structure of Stx2 from E. coli O157:H7 was determined at 1.8-A resolution and compared with the known structure of Stx. Our major finding was that, in contrast to Stx, the active site of the A-subunit of Stx2 is accessible in the holotoxin, and a molecule of formic acid and a water molecule mimic the binding of the adenine base of the substrate. Further, the A-subunit adopts a different orientation with respect to the B-subunits in Stx2 than in Stx, due to interactions between the carboxyl termini of the B-subunits and neighboring regions of the A-subunit. Of the three types of receptor-binding sites in the B-pentamer, one has a different conformation in Stx2 than in Stx, and the carboxyl terminus of the A-subunit binds at another. Any of these structural differences might result in different mechanisms of action of the two toxins and the development of hemolytic uremic syndrome upon exposure to Stx2.
About this StructureAbout this Structure
1R4Q is a Protein complex structure of sequences from Shigella dysenteriae. Full crystallographic information is available from OCA.
ReferenceReference
Structure of shiga toxin type 2 (Stx2) from Escherichia coli O157:H7., Fraser ME, Fujinaga M, Cherney MM, Melton-Celsa AR, Twiddy EM, O'Brien AD, James MN, J Biol Chem. 2004 Jun 25;279(26):27511-7. Epub 2004 Apr 9. PMID:15075327
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