2ds6
Structure of the ZBD in the tetragonal crystal form
OverviewOverview
The degradation of ssrA(AANDENYALAA)-tagged proteins in the bacterial cytosol is carried out by the ClpXP protease and is markedly stimulated by the SspB adaptor protein. It has previously been reported that the amino-terminal zinc-binding domain of ClpX (ZBD) is involved in complex formation with the SspB-tail (XB: ClpX-binding motif). In an effort to better understand the recognition of SspB by ClpX and the mechanism of delivery of ssrA-tagged substrates to ClpXP, we have determined the structures of ZBD alone at 1.5, 2.0, and 2.5 A resolution in each different crystal form and also in complex with XB peptide at 1.6 A resolution. The XB peptide forms an antiparallel beta-sheet with two beta-strands of ZBD, and the structure shows a 1:1 stoichiometric complex between ZBD and XB, suggesting that there are two independent SspB-tail-binding sites in ZBD. The high-resolution ZBD:XB complex structure, in combination with biochemical analyses, can account for key determinants in the recognition of the SspB-tail by ClpX and sheds light on the mechanism of delivery of target proteins to the prokaryotic degradation machine.
About this StructureAbout this Structure
2DS6 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of SspB-tail recognition by the zinc binding domain of ClpX., Park EY, Lee BG, Hong SB, Kim HW, Jeon H, Song HK, J Mol Biol. 2007 Mar 23;367(2):514-26. Epub 2007 Jan 9. PMID:17258768 Page seeded by OCA on Sun May 4 01:05:47 2008