|Gene:||degP||Accession Numbers: EG10463 (MetaCyc), b0161, ECK0160|
Synonyms: htrA, ptd, protease Do
Species: Escherichia coli K-12 substr. MG1655
Subunit composition of serine protease Do = [DegP]6
Protease Do, or DegP, is a periplasmic serine protease required for survival at high temperatures [Lipinska89, Strauch89, Seol91]. DegP degrades abnormal proteins in the periplasm, including mutant proteins, oxidatively damaged proteins and aggregated proteins [Strauch88, Strauch89, SkorkoGlonek99, Laskowska96]. DegP has been specifically shown to degrade the mutant periplasmic protein MalS, as well as unassembled subunits from protein complexes, including HflK, LamB and PapA [Spiess99, Kihara98a, Misra91, Jones02].
DegP also proteolyzes a range of other proteins that may not be quality control substrates, such as the DNA methyltransferare Ada, various forms of the colicin A lysis protein and the replication initiation inhibitor IciA [Lee90, Cavard89, Cavard95, Yoo93]. DegP also binds to the ssrA-encoded degradation tag, though this PDZ-domain-mediated interaction does not appear to allow DegP proteolysis of tagged proteins [Spiers02]. Finally, strains lacking DegP are more susceptible to the cationic antimicrobial peptide Lactoferricin B, indicating a possible role for DegP in degradation of that molecule [Ulvatne02].
DegP also has an independent chaperone activity that functions even in proteolytically inactive mutants of DegP [Spiess99]. This chaperone activity is required for survival in the case of disrupted outer membrane assembly, preventing buildup of toxic aggregates [Misra00]. There may be some redundancy between DegP and the chaperones Skp and SurA [Rizzitello01].
DegP is a six-membered ring-shaped structure with a central cavity which contains its proteolytic sites [Swamy83, Kim99b]. The hexamer is built from a pair of staggered trimeric rings, with the proteolytic cavity accessible from the sides rather than the ends [Krojer02]. There are two PDZ domains in each monomer which are required for this assembly, and which may be involved in opening and closing the lateral openings [Sassoon99]. Binding of substrate to the PDZ1 domain induces oligomer conversion from a resting hexameric state to a higher order active complex [Krojer10, Merdanovic10]. The PDZ1 domain anchors substrate, facilitating its presentation to the proteolytic domain [Krojer08]. DegP is a processive protease - cleaving its substrate into peptides with a mean size of 13-15 residues [Krojer08]. The PDZ1 domain is required for protease activity and for binding of unfolded proteins, while the PDZ2 domain is primarily required for maintaining a hexameric configuration [Iwanczyk07]. The inner cavity also has several hydrophobic patches, which may be involved in its chaperone function [Krojer02].
Hexameric DegP assembles into large catalytically active spherical structures around its substrate [Krojer08a, Jiang08]. The spherical multimers exhibit proteolytic and chaperone-like activity [Shen09]. A model polypeptide substrate binds each DegP subunit at two sites in the crystal structure of a DegP dodecamer [Kim11]. Substrate binding drives the formation of proteolytically active dodecamers and larger cages of 18, 24 and 30 subunits while substrate cleavage promotes cage disassembly [Kim11].
DegP's proteolytic activity is increased at high temperatures but drops dramatically at low temperatures, leaving its chaperone function unaffected [SkorkoGlonek95, Spiess99]. DegP interacts with phosphatidylglycerol on the periplasmic face of the inner membrane, undergoing a conformational change that correlates with the temperature dependence of its proteolytic capacity [SkorkoGlonek97].
The mature form of DegP is derived by cleavage of its first twenty-six amino acids by leader peptidase [Lipinska90, Lipinska89]. Targeting of DegP to the Sec-translocase for transport across the inner membrane is SecB-dependent [Baars06].
DegP is a member of the HtrA (high temperature requirement) family of proteases which combine a protease domain with one or more PDZ domains and function as higher order oligomers [Kim05a].
DegP is downregulated during low osmolarity [Forns05].
Locations: inner membrane, periplasmic space
|Map Position: [180,884 -> 182,308]|
Molecular Weight of Polypeptide: 49.354 kD (from nucleotide sequence)
Unification Links: ASAP:ABE-0000551 , CGSC:30554 , DIP:DIP-46256N , EchoBASE:EB0458 , EcoGene:EG10463 , EcoliWiki:b0161 , EcoO157Cyc:HTRA-MONOMER , Mint:MINT-1302319 , ModBase:P0C0V0 , OU-Microarray:b0161 , PortEco:degP , PR:PRO_000022425 , Pride:P0C0V0 , Protein Model Portal:P0C0V0 , RefSeq:NP_414703 , RegulonDB:EG10463 , SMR:P0C0V0 , String:511145.b0161 , Swiss-Model:P0C0V0 , UniProt:P0C0V0
Relationship Links: InterPro:IN-FAMILY:IPR001478 , InterPro:IN-FAMILY:IPR001940 , InterPro:IN-FAMILY:IPR009003 , InterPro:IN-FAMILY:IPR011782 , PDB:Structure:1KY9 , PDB:Structure:2ZLE , PDB:Structure:3CS0 , PDB:Structure:3MH4 , PDB:Structure:3MH5 , PDB:Structure:3MH6 , PDB:Structure:3MH7 , PDB:Structure:3OTP , PDB:Structure:3OU0 , PDB:Structure:4A8D , Pfam:IN-FAMILY:PF00595 , Prints:IN-FAMILY:PR00834 , Prosite:IN-FAMILY:PS50106 , Smart:IN-FAMILY:SM00228
|Biological Process:||GO:0006457 - protein folding
GO:0006508 - proteolysis [UniProtGOA11a, GOA01a, Lipinska90]
GO:0006515 - misfolded or incompletely synthesized protein catabolic process [Spiess99]
GO:0006979 - response to oxidative stress [SkorkoGlonek99]
GO:0009266 - response to temperature stimulus [Spiess99]
GO:0006950 - response to stress [UniProtGOA11a]
|Molecular Function:||GO:0004252 - serine-type endopeptidase activity
[GOA01a, Lipinska90, Shen09]
GO:0005515 - protein binding [Ge14, Kim11]
GO:0042802 - identical protein binding [Kim11]
GO:0003824 - catalytic activity [GOA01a]
GO:0008233 - peptidase activity [UniProtGOA11a]
GO:0008236 - serine-type peptidase activity [UniProtGOA11a]
GO:0016787 - hydrolase activity [UniProtGOA11a]
|Cellular Component:||GO:0030288 - outer membrane-bounded periplasmic space
GO:0005886 - plasma membrane [UniProtGOA11, UniProtGOA11a]
GO:0016020 - membrane [UniProtGOA11a]
|MultiFun Terms:||cell processes → adaptations → other (mechanical, nutritional, oxidative stress)|
|cell processes → adaptations → temperature extremes|
|information transfer → protein related → turnover, degradation|
|metabolism → degradation of macromolecules → proteins/peptides/glycopeptides|
Enzymatic reaction of: serine protease
EC Number: 3.4.21.-
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
The reaction is physiologically favored in the direction shown.
|Signal-Sequence||1 -> 26|
|Chain||27 -> 474|
|Protein-Segment||234 -> 236|
|Protein-Segment||252 -> 256|
|Conserved-Region||280 -> 371|
|Protein-Segment||291 -> 295|
|Conserved-Region||377 -> 466|
|Sequence-Conflict||467 -> 474|
10/20/97 Gene b0161 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10463; confirmed by SwissProt match.
Baars06: Baars L, Ytterberg AJ, Drew D, Wagner S, Thilo C, van Wijk KJ, de Gier JW (2006). "Defining the role of the Escherichia coli chaperone SecB using comparative proteomics." J Biol Chem 281(15);10024-34. PMID: 16352602
Forns05: Forns N, Juarez A, Madrid C (2005). "Osmoregulation of the HtrA (DegP) protease of Escherichia coli: an Hha-H-NS complex represses HtrA expression at low osmolarity." FEMS Microbiol Lett 251(1);75-80. PMID: 16143461
Ge14: Ge X, Wang R, Ma J, Liu Y, Ezemaduka AN, Chen PR, Fu X, Chang Z (2014). "DegP primarily functions as a protease for the biogenesis of β-barrel outer membrane proteins in the Gram-negative bacterium Escherichia coli." FEBS J 281(4):1226-1240. PMID: 24373465
Iwanczyk07: Iwanczyk J, Damjanovic D, Kooistra J, Leong V, Jomaa A, Ghirlando R, Ortega J (2007). "Role of the PDZ domains in Escherichia coli DegP protein." J Bacteriol 189(8);3176-86. PMID: 17277057
Jiang08: Jiang J, Zhang X, Chen Y, Wu Y, Zhou ZH, Chang Z, Sui SF (2008). "Activation of DegP chaperone-protease via formation of large cage-like oligomers upon binding to substrate proteins." Proc Natl Acad Sci U S A 105(33);11939-44. PMID: 18697939
Jones02: Jones CH, Dexter P, Evans AK, Liu C, Hultgren SJ, Hruby DE (2002). "Escherichia coli DegP protease cleaves between paired hydrophobic residues in a natural substrate: the PapA pilin." J Bacteriol 184(20);5762-71. PMID: 12270835
Kim99b: Kim KI, Park SC, Kang SH, Cheong GW, Chung CH (1999). "Selective degradation of unfolded proteins by the self-compartmentalizing HtrA protease, a periplasmic heat shock protein in Escherichia coli." J Mol Biol 294(5);1363-74. PMID: 10600391
Krojer08: Krojer T, Pangerl K, Kurt J, Sawa J, Stingl C, Mechtler K, Huber R, Ehrmann M, Clausen T (2008). "Interplay of PDZ and protease domain of DegP ensures efficient elimination of misfolded proteins." Proc Natl Acad Sci U S A 105(22);7702-7. PMID: 18505836
Krojer10: Krojer T, Sawa J, Huber R, Clausen T (2010). "HtrA proteases have a conserved activation mechanism that can be triggered by distinct molecular cues." Nat Struct Mol Biol 17(7);844-52. PMID: 20581825
Laskowska96: Laskowska E, Kuczynska-Wisnik D, Skorko-Glonek J, Taylor A (1996). "Degradation by proteases Lon, Clp and HtrA, of Escherichia coli proteins aggregated in vivo by heat shock; HtrA protease action in vivo and in vitro." Mol Microbiol 22(3);555-71. PMID: 8939438
Lee90: Lee CS, Hahm JK, Hwang BJ, Park KC, Ha DB, Park SD, Chung CH (1990). "Processing of Ada protein by two serine endoproteases Do and So from Escherichia coli." FEBS Lett 262(2);310-2. PMID: 2159417
Lipinska88: Lipinska B, Sharma S, Georgopoulos C (1988). "Sequence analysis and regulation of the htrA gene of Escherichia coli: a sigma 32-independent mechanism of heat-inducible transcription." Nucleic Acids Res 16(21);10053-67. PMID: 3057437
Lipinska89: Lipinska B, Fayet O, Baird L, Georgopoulos C (1989). "Identification, characterization, and mapping of the Escherichia coli htrA gene, whose product is essential for bacterial growth only at elevated temperatures." J Bacteriol 171(3);1574-84. PMID: 2537822
Lipinska90: Lipinska B, Zylicz M, Georgopoulos C (1990). "The HtrA (DegP) protein, essential for Escherichia coli survival at high temperatures, is an endopeptidase." J Bacteriol 172(4);1791-7. PMID: 2180903
Merdanovic10: Merdanovic M, Mamant N, Meltzer M, Poepsel S, Auckenthaler A, Melgaard R, Hauske P, Nagel-Steger L, Clarke AR, Kaiser M, Huber R, Ehrmann M (2010). "Determinants of structural and functional plasticity of a widely conserved protease chaperone complex." Nat Struct Mol Biol 17(7);837-43. PMID: 20581826
Misra00: Misra R, CastilloKeller M, Deng M (2000). "Overexpression of protease-deficient DegP(S210A) rescues the lethal phenotype of Escherichia coli OmpF assembly mutants in a degP background." J Bacteriol 182(17);4882-8. PMID: 10940032
Misra91: Misra R, Peterson A, Ferenci T, Silhavy TJ (1991). "A genetic approach for analyzing the pathway of LamB assembly into the outer membrane of Escherichia coli." J Biol Chem 266(21);13592-7. PMID: 1856196
Pan03: Pan KL, Hsiao HC, Weng CL, Wu MS, Chou CP (2003). "Roles of DegP in prevention of protein misfolding in the periplasm upon overexpression of penicillin acylase in Escherichia coli." J Bacteriol 185(10);3020-30. PMID: 12730160
Quirk90: Quirk S, Bhatnagar SK, Bessman MJ (1990). "Primary structure of the deoxyguanosine triphosphate triphosphohydrolase-encoding gene (dgt) of Escherichia coli." Gene 1990;89(1);13-8. PMID: 2165018
Rizzitello01: Rizzitello AE, Harper JR, Silhavy TJ (2001). "Genetic evidence for parallel pathways of chaperone activity in the periplasm of Escherichia coli." J Bacteriol 183(23);6794-800. PMID: 11698367
Seol91: Seol JH, Woo SK, Jung EM, Yoo SJ, Lee CS, Kim KJ, Tanaka K, Ichihara A, Ha DB, Chung CH (1991). "Protease Do is essential for survival of Escherichia coli at high temperatures: its identity with the htrA gene product." Biochem Biophys Res Commun 176(2);730-6. PMID: 2025286
Shen09: Shen QT, Bai XC, Chang LF, Wu Y, Wang HW, Sui SF (2009). "Bowl-shaped oligomeric structures on membranes as DegP's new functional forms in protein quality control." Proc Natl Acad Sci U S A 106(12);4858-63. PMID: 19255437
SkorkoGlonek03: Skorko-Glonek J, Zurawa D, Tanfani F, Scire A, Wawrzynow A, Narkiewicz J, Bertoli E, Lipinska B (2003). "The N-terminal region of HtrA heat shock protease from Escherichia coli is essential for stabilization of HtrA primary structure and maintaining of its oligomeric structure." Biochim Biophys Acta 1649(2);171-82. PMID: 12878036
SkorkoGlonek95: Skorko-Glonek J, Krzewski K, Lipinska B, Bertoli E, Tanfani F (1995). "Comparison of the structure of wild-type HtrA heat shock protease and mutant HtrA proteins. A Fourier transform infrared spectroscopic study." J Biol Chem 270(19);11140-6. PMID: 7744744
SkorkoGlonek95a: Skorko-Glonek J, Wawrzynow A, Krzewski K, Kurpierz K, Lipinska B (1995). "Site-directed mutagenesis of the HtrA (DegP) serine protease, whose proteolytic activity is indispensable for Escherichia coli survival at elevated temperatures." Gene 163(1);47-52. PMID: 7557477
SkorkoGlonek97: Skorko-Glonek J, Lipinska B, Krzewski K, Zolese G, Bertoli E, Tanfani F (1997). "HtrA heat shock protease interacts with phospholipid membranes and undergoes conformational changes." J Biol Chem 272(14);8974-82. PMID: 9083020
SkorkoGlonek99: Skorko-Glonek J, Zurawa D, Kuczwara E, Wozniak M, Wypych Z, Lipinska B (1999). "The Escherichia coli heat shock protease HtrA participates in defense against oxidative stress." Mol Gen Genet 262(2);342-50. PMID: 10517331
SobieckaSzkatul10: Sobiecka-Szkatula A, Gieldon A, Scire A, Tanfani F, Figaj D, Koper T, Ciarkowski J, Lipinska B, Skorko-Glonek J (2010). "The role of the L2 loop in the regulation and maintaining the proteolytic activity of HtrA (DegP) protein from Escherichia coli." Arch Biochem Biophys 500(2);123-30. PMID: 20515644
Spiers02: Spiers A, Lamb HK, Cocklin S, Wheeler KA, Budworth J, Dodds AL, Pallen MJ, Maskell DJ, Charles IG, Hawkins AR (2002). "PDZ domains facilitate binding of high temperature requirement protease A (HtrA) and tail-specific protease (Tsp) to heterologous substrates through recognition of the small stable RNA A (ssrA)-encoded peptide." J Biol Chem 277(42);39443-9. PMID: 12177052
Strauch89: Strauch KL, Johnson K, Beckwith J (1989). "Characterization of degP, a gene required for proteolysis in the cell envelope and essential for growth of Escherichia coli at high temperature." J Bacteriol 171(5);2689-96. PMID: 2540154
Swamy83: Swamy KH, Chung CH, Goldberg AL (1983). "Isolation and characterization of protease do from Escherichia coli, a large serine protease containing multiple subunits." Arch Biochem Biophys 224(2);543-54. PMID: 6347072
Ulvatne02: Ulvatne H, Haukland HH, Samuelsen O, Kramer M, Vorland LH (2002). "Proteases in Escherichia coli and Staphylococcus aureus confer reduced susceptibility to lactoferricin B." J Antimicrob Chemother 50(4);461-7. PMID: 12356789
Yoo93: Yoo SJ, Seol JH, Woo SK, Suh SW, Hwang DS, Ha DB, Chung CH (1993). "Hydrolysis of the IciA protein, an inhibitor of DNA replication initiation, by protease Do in Escherichia coli." FEBS Lett 327(1);17-20. PMID: 8335089
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