Structural highlights
Function
SSPB_ECOLI Enhances recognition of ssrA-tagged proteins by the ClpX-ClpP protease; the ssrA degradation tag (AANDENYALAA) is added trans-translationally to proteins that are stalled on the ribosome, freeing the ribosome and targeting stalled peptides for degradation. SspB activates the ATPase activity of ClpX. Seems to act in concert with SspA in the regulation of several proteins during exponential and stationary-phase growth.[1] [2] [3] Also stimulates degradation of the N-terminus of RseA (residues 1-108, alone or in complex with sigma-E) by ClpX-ClpP in a non-ssrA-mediated fashion.[4] [5] [6]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Energy-dependent proteases often rely on adaptor proteins to modulate substrate recognition. The SspB adaptor binds peptide sequences in the stress-response regulator RseA and in ssrA-tagged proteins and delivers these molecules to the AAA+ ClpXP protease for degradation. The structure of SspB bound to an ssrA peptide is known. Here, we report the crystal structure of a complex between SspB and its recognition peptide in RseA. Notably, the RseA sequence is positioned in the peptide-binding groove of SspB in a direction opposite to the ssrA peptide, the two peptides share only one common interaction with the adaptor, and the RseA interaction site is substantially larger than the overlapping ssrA site. This marked diversity in SspB recognition of different target proteins indicates that it is capable of highly flexible and dynamic substrate delivery.
Versatile modes of peptide recognition by the AAA+ adaptor protein SspB.,Levchenko I, Grant RA, Flynn JM, Sauer RT, Baker TA Nat Struct Mol Biol. 2005 Jun;12(6):520-5. Epub 2005 May 8. PMID:15880122[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Levchenko I, Seidel M, Sauer RT, Baker TA. A specificity-enhancing factor for the ClpXP degradation machine. Science. 2000 Sep 29;289(5488):2354-6. PMID:11009422
- ↑ Flynn JM, Levchenko I, Sauer RT, Baker TA. Modulating substrate choice: the SspB adaptor delivers a regulator of the extracytoplasmic-stress response to the AAA+ protease ClpXP for degradation. Genes Dev. 2004 Sep 15;18(18):2292-301. PMID:15371343 doi:http://dx.doi.org/10.1101/gad.1240104
- ↑ Song HK, Eck MJ. Structural basis of degradation signal recognition by SspB, a specificity-enhancing factor for the ClpXP proteolytic machine. Mol Cell. 2003 Jul;12(1):75-86. PMID:12887894
- ↑ Levchenko I, Seidel M, Sauer RT, Baker TA. A specificity-enhancing factor for the ClpXP degradation machine. Science. 2000 Sep 29;289(5488):2354-6. PMID:11009422
- ↑ Flynn JM, Levchenko I, Sauer RT, Baker TA. Modulating substrate choice: the SspB adaptor delivers a regulator of the extracytoplasmic-stress response to the AAA+ protease ClpXP for degradation. Genes Dev. 2004 Sep 15;18(18):2292-301. PMID:15371343 doi:http://dx.doi.org/10.1101/gad.1240104
- ↑ Song HK, Eck MJ. Structural basis of degradation signal recognition by SspB, a specificity-enhancing factor for the ClpXP proteolytic machine. Mol Cell. 2003 Jul;12(1):75-86. PMID:12887894
- ↑ Levchenko I, Grant RA, Flynn JM, Sauer RT, Baker TA. Versatile modes of peptide recognition by the AAA+ adaptor protein SspB. Nat Struct Mol Biol. 2005 Jun;12(6):520-5. Epub 2005 May 8. PMID:15880122 doi:10.1038/nsmb934
