| Structural highlights
3otp is a 12 chain structure with sequence from Escherichia coli and Gallus gallus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Related: | 3ou0, 3cs0 |
| Gene: | b0161, degP, htrA, JW0157, ptd (Escherichia coli), lysozyme C, LYZ (Gallus gallus) |
| Activity: | Lysozyme, with EC number 3.2.1.17 |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[DEGP_ECOLI] DegP acts as a chaperone at low temperatures but switches to a peptidase (heat shock protein) at higher temperatures. It degrades transiently denatured and unfolded proteins which accumulate in the periplasm following heat shock or other stress conditions. DegP is efficient with Val-Xaa and Ile-Xaa peptide bonds, suggesting a preference for beta-branched side chain amino acids. Only unfolded proteins devoid of disulfide bonds appear capable of being cleaved, thereby preventing non-specific proteolysis of folded proteins. Its proteolytic activity is essential for the survival of cells at elevated temperatures. It can degrade IciA, ada, casein, globin and PapA. DegP shares specificity with DegQ. DegP is also involved in the biogenesis of partially folded outer-membrane proteins (OMP).[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
Protein quality control requires careful regulation of intracellular proteolysis. For DegP, a periplasmic protease, substrates promote assembly of inactive hexamers into proteolytically active cages with 12, 18, 24, or 30 subunits. Here, we show that sensitive activation and cage assembly require covalent linkage of distinct substrate sequences that affect degradation (degrons). One degron binds the DegP active site, and another degron binds a separate tethering site in PDZ1 in the crystal structure of a substrate-bound DegP dodecamer. FRET experiments demonstrate that active cages assemble rapidly in a reaction that is positively cooperative in substrate concentration, remain stably assembled while uncleaved substrate is present, and dissociate once degradation is complete. Thus, the energy of binding of linked substrate degrons drives assembly of the proteolytic machine responsible for subsequent degradation. Substrate cleavage and depletion results in disassembly, ensuring that DegP is proteolytically active only when sufficient quantities of protein substrates are present.
Covalent Linkage of Distinct Substrate Degrons Controls Assembly and Disassembly of DegP Proteolytic Cages.,Kim S, Grant RA, Sauer RT Cell. 2011 Apr 1;145(1):67-78. PMID:21458668[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Lipinska B, Zylicz M, Georgopoulos C. The HtrA (DegP) protein, essential for Escherichia coli survival at high temperatures, is an endopeptidase. J Bacteriol. 1990 Apr;172(4):1791-7. PMID:2180903
- ↑ Kolmar H, Waller PR, Sauer RT. The DegP and DegQ periplasmic endoproteases of Escherichia coli: specificity for cleavage sites and substrate conformation. J Bacteriol. 1996 Oct;178(20):5925-9. PMID:8830688
- ↑ Spiess C, Beil A, Ehrmann M. A temperature-dependent switch from chaperone to protease in a widely conserved heat shock protein. Cell. 1999 Apr 30;97(3):339-47. PMID:10319814
- ↑ Krojer T, Pangerl K, Kurt J, Sawa J, Stingl C, Mechtler K, Huber R, Ehrmann M, Clausen T. Interplay of PDZ and protease domain of DegP ensures efficient elimination of misfolded proteins. Proc Natl Acad Sci U S A. 2008 Jun 3;105(22):7702-7. doi:, 10.1073/pnas.0803392105. Epub 2008 May 27. PMID:18505836 doi:10.1073/pnas.0803392105
- ↑ Pan KL, Hsiao HC, Weng CL, Wu MS, Chou CP. Roles of DegP in prevention of protein misfolding in the periplasm upon overexpression of penicillin acylase in Escherichia coli. J Bacteriol. 2003 May;185(10):3020-30. PMID:12730160
- ↑ Krojer T, Sawa J, Schafer E, Saibil HR, Ehrmann M, Clausen T. Structural basis for the regulated protease and chaperone function of DegP. Nature. 2008 Jun 12;453(7197):885-90. Epub 2008 May 21. PMID:18496527 doi:10.1038/nature07004
- ↑ Kim S, Grant RA, Sauer RT. Covalent Linkage of Distinct Substrate Degrons Controls Assembly and Disassembly of DegP Proteolytic Cages. Cell. 2011 Apr 1;145(1):67-78. PMID:21458668 doi:10.1016/j.cell.2011.02.024
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