Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Periplasmic protein CpxP

Gene

cpxP

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Acts as an auxiliary protein in the Cpx two-component envelope stress response system, helping modulate the Cpx response systems response to some inducers (PubMed:25207645, PubMed:16303867). Binds the periplasmic domain of sensor histidine kinase CpxA, inhibiting induction of the Cpx envelope stress response in the absence of inducer; overexpression decreases Cpx pathway activity (PubMed:16166523, PubMed:21317318). Some periplasmic stimulii (shown for P pili subunit PapE and probably 0.3 M NaCl) increase CpxP's susceptibility to DegP, leading to CpxP degradation, inducing the Cpx pathway (PubMed:16166523, PubMed:16303867). Aids in combating extracytoplasmic protein-mediated toxicity (PubMed:9473036, PubMed:16303867, PubMed:21239493). Overexpression leads to degradation by DegP of misfolded P pili subunits in the periplasm (tested using PapE) (PubMed:21239493). Inhibits autophosphorylation of CpxA in reconstituted liposomes by 50% but has no effect on phosphatase activity of CpxA (PubMed:17259177, PubMed:21239493). Has mild protein chaperone activity (PubMed:21317898, PubMed:21239493).8 Publications

GO - Molecular functioni

  • identical protein binding Source: IntAct
  • unfolded protein binding Source: EcoCyc

GO - Biological processi

  • negative regulation of transcription, DNA-templated Source: EcoCyc

Keywordsi

Biological processStress response

Enzyme and pathway databases

BioCyciEcoCyc:G7816-MONOMER

Names & Taxonomyi

Protein namesi
Recommended name:
Periplasmic protein CpxP1 Publication
Alternative name(s):
ORF_o1671 Publication
Periplasmic accessory protein CpxP
Gene namesi
Name:cpxP1 Publication
Synonyms:yiiO
Ordered Locus Names:b4484, JW5558
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG11872 cpxP

Subcellular locationi

  • Periplasm 2 Publications

GO - Cellular componenti

  • outer membrane-bounded periplasmic space Source: EcoCyc

Keywords - Cellular componenti

Periplasm

Pathology & Biotechi

Disruption phenotypei

Hypersensitive to alkaline pH (greater than pH 8.8) (PubMed:9473036). Increased accumulation and toxicity of overexpressed, misfolded periplasmic proteins (PubMed:16303867).2 Publications

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi55Q → P: No longer inhibits Cpx pathway, protein more susceptible to DegP. 2 Publications1
Mutagenesisi56R → Q: No longer interacts with CpxA. 1 Publication1
Mutagenesisi59M → T: No longer inhibits Cpx pathway, protein more susceptible to DegP. 1 Publication1
Mutagenesisi60R → Q: No longer inhibits Cpx pathway. 1 Publication1
Mutagenesisi61D → E or V: No longer inhibits Cpx pathway. 1 Publication1
Mutagenesisi103A → D or G: Decreased protein stability, significantly reduced degradation of PapE. 1 Publication1
Mutagenesisi107I → D: Decreased protein stability, significantly reduced degradation of PapE. 1 Publication1
Mutagenesisi107I → G or N: Decreased protein stability, wild-type degradation of PapE. 1 Publication1
Mutagenesisi108A → D: Decreased protein stability, significantly reduced degradation of PapE. 1 Publication1
Mutagenesisi108A → G: Decreased protein stability, wild-type degradation of PapE. 1 Publication1
Mutagenesisi108A → V: Decreased protein stability, significantly reduced degradation of PapE, retains most Cpx inhibition activity. 2 Publications1
Mutagenesisi128Q → H: No longer inhibits Cpx pathway in wild-type cells, protein more susceptible to DegP, in the absence of DegP protease partially inhibits Cpx. 2 Publications1

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 21Sequence analysisAdd BLAST21
ChainiPRO_000002099222 – 166Periplasmic protein CpxPAdd BLAST145

Post-translational modificationi

Degraded by DegP; some CpxP mutant proteins are more susceptible to the protease than others (PubMed:16166523). Degradation probably occurs when CpxP is associated with some misfolded proteins; overexpression of PapE leads to DegP-mediated degradation of CpxP and PapE, which requires the N-terminus of PapE. Overexpression of NlpE does not induce this degradation however (PubMed:16303867).2 Publications

Proteomic databases

PaxDbiP0AE85
PRIDEiP0AE85

Expressioni

Inductioni

Induced by envelope stress such as overexpression of misfolded periplasmic proteins (PubMed:9351822). Induced by alkaine pH (tested up to pH 8.4) (PubMed:9473036, PubMed:16166523). Induction is decreased in a degP deletion (PubMed:16166523). Transcription is stimulated by the Cpx two-component signal transduction pathway; sigma factor E (rpoE) is not involved (PubMed:9351822, PubMed:9473036, PubMed:10972835). Transcription induced by spheroplasting, which removes the periplasm and thus this protein; if the protein is anchored to the outer surface of the inner membrane induction does not occur (PubMed:10972835). Induced in persister cells (PubMed:16768798).5 Publications

Interactioni

Subunit structurei

Homodimer; it might alter shape slightly at pH 8.0 when Cpx is induced (PubMed:21317318, PubMed:21239493). Binds the periplasmic sensor domain of CpxA (PubMed:16166523, PubMed:21317318, PubMed:21239493, PubMed:25207645). Interaction with CpxA is not seen in vivo when cells are grown in 0.3 M NaCl, or if the misfolded P pili protein PapE is overexpressed (PubMed:25207645).1 Publication3 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
itself2EBI-6413881,EBI-6413881

GO - Molecular functioni

  • identical protein binding Source: IntAct
  • unfolded protein binding Source: EcoCyc

Protein-protein interaction databases

BioGridi4262646, 127 interactors
DIPiDIP-47937N
IntActiP0AE85, 4 interactors
STRINGi316385.ECDH10B_4103

Structurei

Secondary structure

1166
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Turni45 – 48Combined sources4
Helixi53 – 69Combined sources17
Helixi75 – 85Combined sources11
Beta strandi87 – 89Combined sources3
Helixi92 – 121Combined sources30
Helixi126 – 142Combined sources17
Helixi146 – 149Combined sources4

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3ITFX-ray1.45A/B21-150[»]
3QZCX-ray2.85A/B40-151[»]
ProteinModelPortaliP0AE85
SMRiP0AE85
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP0AE85

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni55 – 61Important for protein stability, probably interacts with CpxA1 Publication7
Regioni151 – 166Not required for activation of CpxA or to induce degradation of misfolded P pili subunits1 PublicationAdd BLAST16

Domaini

A region in the N-terminus (residues 55-61) probably interacts with the periplasmic sensor domain of CpxA to inhibit its kinase activity and is also important for CpxP stability (PubMed:16166523). The homodimer has an elongated cradle shape; a hydrophobic cleft on the convex face may interact with periplasmic protein PapE (PubMed:21239493).2 Publications

Sequence similaritiesi

Belongs to the CpxP/Spy family.Curated

Keywords - Domaini

Signal

Phylogenomic databases

eggNOGiENOG4105FMW Bacteria
COG3678 LUCA
HOGENOMiHOG000285733
InParanoidiP0AE85
KOiK06006
OMAiNERMQEC

Family and domain databases

CDDicd09916 CpxP_like, 1 hit
InterProiView protein in InterPro
IPR012899 LTXXQ
PfamiView protein in Pfam
PF07813 LTXXQ, 1 hit
PIRSFiPIRSF034445 CpxP_Spy, 1 hit

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P0AE85-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MRIVTAAVMA STLAVSSLSH AAEVGSGDNW HPGEELTQRS TQSHMFDGIS
60 70 80 90 100
LTEHQRQQMR DLMQQARHEQ PPVNVSELET MHRLVTAENF DENAVRAQAE
110 120 130 140 150
KMANEQIARQ VEMAKVRNQM YRLLTPEQQA VLNEKHQQRM EQLRDVTQWQ
160
KSSSLKLLSS SNSRSQ
Length:166
Mass (Da):18,965
Last modified:December 6, 2005 - v1
Checksum:iBD517D2D14D90209
GO

Sequence cautioni

The sequence AAB03046 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L19201 Genomic DNA Translation: AAB03046.1 Different initiation.
U00096 Genomic DNA Translation: AAT48235.1
AP009048 Genomic DNA Translation: BAE77396.1
RefSeqiWP_001223800.1, NZ_LN832404.1
YP_026277.1, NC_000913.3

Genome annotation databases

EnsemblBacteriaiAAT48235; AAT48235; b4484
BAE77396; BAE77396; BAE77396
GeneIDi2847688
KEGGiecj:JW5558
eco:b4484
PATRICifig|1411691.4.peg.2791

Similar proteinsi

Entry informationi

Entry nameiCPXP_ECOLI
AccessioniPrimary (citable) accession number: P0AE85
Secondary accession number(s): O65939, P32158, Q2M8L0
Entry historyiIntegrated into UniProtKB/Swiss-Prot: December 6, 2005
Last sequence update: December 6, 2005
Last modified: March 28, 2018
This is version 88 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health