1twb
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= SSPB, HI1440 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=727 Haemophilus influenzae]) | |GENE= SSPB, HI1440 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=727 Haemophilus influenzae]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1twb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1twb OCA], [http://www.ebi.ac.uk/pdbsum/1twb PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1twb RCSB]</span> | ||
}} | }} | ||
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[[Category: specificity factor]] | [[Category: specificity factor]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:02:02 2008'' |
Revision as of 21:02, 30 March 2008
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| , resolution 1.90Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | SSPB, HI1440 (Haemophilus influenzae) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
SspB disulfide crosslinked to an ssrA degradation tag
Overview
The SspB adaptor enhances ClpXP degradation by binding the ssrA degradation tag of substrates and the AAA+ ClpX unfoldase. To probe the mechanism of substrate delivery, we engineered a disulfide bond between the ssrA tag and SspB and demonstrated otherwise normal interactions by solving the crystal structure. Although the covalent link prevents adaptor.substrate dissociation, ClpXP degraded GFP-ssrA that was disulfide bonded to the adaptor. Thus, crosslinked substrate must be handed directly from SspB to ClpX. The ssrA tag in the covalent adaptor complex interacted with ClpX.ATPgammaS but not ClpX.ADP, suggesting that handoff occurs in the ATP bound enzyme. By contrast, SspB alone bound ClpX in both nucleotide states. Similar handoff mechanisms will undoubtedly be used by many AAA+ adaptors and enzymes, allowing assembly of delivery complexes in either nucleotide state, engagement of the recognition tag in the ATP state, and application of an unfolding force to the attached protein following hydrolysis.
About this Structure
1TWB is a Single protein structure of sequence from Haemophilus influenzae. Full crystallographic information is available from OCA.
Reference
Nucleotide-dependent substrate handoff from the SspB adaptor to the AAA+ ClpXP protease., Bolon DN, Grant RA, Baker TA, Sauer RT, Mol Cell. 2004 Nov 5;16(3):343-50. PMID:15525508
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