id: P0AE52
gene_symbol: bcp
product_type: PROTEIN
status: DRAFT
taxon:
  id: NCBITaxon:83333
  label: Escherichia coli (strain K12)
description: >-
  Bcp (bacterioferritin comigratory protein) is a monomeric peroxiredoxin of
  the BCP/PrxQ subfamily (EC 1.11.1.24) that catalyzes the thioredoxin-dependent
  reduction of hydrogen peroxide and organic hydroperoxides to water and the
  corresponding alcohols. It functions as an atypical 2-Cys peroxiredoxin: the
  peroxidatic cysteine Cys45 is oxidized to sulfenic acid by peroxide, then
  forms an intramolecular disulfide with the resolving cysteine Cys50, which
  is subsequently reduced by thioredoxin. Unlike the major E. coli peroxiredoxin
  AhpC, BCP is unusually versatile -- it can use multiple electron donors
  (Trx1, Trx2, Grx1, Grx3), has the highest redox potential (-146 mV) of any
  characterized peroxiredoxin, and shows broad peroxide substrate specificity.
  These properties suggest BCP may serve as a defense enzyme of last resort,
  remaining active under highly oxidizing conditions when other antioxidant
  systems are compromised. The bcp null mutant shows hypersensitivity to
  H2O2, tert-butyl hydroperoxide, and linoleic acid hydroperoxide, confirming
  its role in oxidative stress defense.
existing_annotations:
- term:
    id: GO:0008379
    label: thioredoxin peroxidase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      BCP has well-characterized thioredoxin-dependent peroxidase activity.
      The IBA annotation from phylogenetic inference is strongly supported by
      direct experimental evidence in the same organism (see IDA annotation below).
      BCP uses thioredoxin as a primary electron donor to reduce hydroperoxides.
    action: ACCEPT
    reason: >-
      Thioredoxin peroxidase activity is the core molecular function of BCP,
      demonstrated by Jeong et al. (2000) and characterized in detail by
      Reeves et al. (2011). The phylogenetic inference is correct and
      consistent with direct experimental data.
    supported_by:
    - reference_id: PMID:10644761
      supporting_text: "BCP showed a thioredoxin-dependent thiol peroxidase activity"
    - reference_id: PMID:21910476
      supporting_text: "thioredoxin (Trx1)-dependent peroxidase assays conducted by stopped-flow spectroscopy"
    - reference_id: file:ECOLI/bcp/bcp-deep-research-falcon.md
      supporting_text: |-
        described as an unusually versatile bacterial peroxiredoxin
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      Cytoplasmic localization is correct for BCP. The protein lacks signal
      peptides and transmembrane domains and is a soluble monomeric enzyme.
      Two independent proteomics studies confirmed cytosolic localization.
      The broader cytoplasm annotation subsumes the more specific cytosol
      IDA annotations.
    action: ACCEPT
    reason: >-
      BCP is a soluble cytoplasmic enzyme. This is supported by two
      independent large-scale proteomics studies that identified BCP in the
      cytosolic fraction of E. coli K-12.
    supported_by:
    - reference_id: PMID:15911532
      supporting_text: "a proteomic analysis of Escherichia coli in which 3,199 protein forms were detected, and of those 2,160 were annotated and assigned to the cytosol, periplasm, inner membrane, and outer membrane"
    - reference_id: PMID:18304323
      supporting_text: "we identified 1103 proteins from the cytosolic fraction of the Escherichia coli strain MC4100"
    - reference_id: file:ECOLI/bcp/bcp-deep-research-falcon.md
      supporting_text: |-
        BCP is best supported as a **cytosolic peroxide-detoxifying enzyme** integrated with NADPH-driven thioredoxin/glutaredoxin systems
- term:
    id: GO:0034599
    label: cellular response to oxidative stress
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      BCP is involved in the cellular response to oxidative stress. The bcp
      null mutant shows hypersensitivity to multiple oxidants, and bcp expression
      is induced 3-fold upon shift from anaerobic to aerobic growth. However,
      GO:0034599 (cellular response to oxidative stress) implies a signaling
      or regulatory response component beyond simple detoxification. While
      UniProt states BCP acts "as sensor of hydrogen peroxide-mediated signaling
      events," the evidence for a signaling role in E. coli BCP is limited.
      The more straightforward annotation GO:0006979 (response to oxidative
      stress, IMP) is already present and better supported.
    action: KEEP_AS_NON_CORE
    reason: >-
      The annotation is not wrong but the more specific claim of "cellular
      response" (implying regulation/signaling) is less well-supported than
      the general oxidative stress response role. The IMP annotation to
      GO:0006979 below provides stronger direct evidence for the core
      oxidative stress defense function.
    supported_by:
    - reference_id: PMID:10644761
      supporting_text: "BCP was induced 3-fold by the oxidative stress given by changing the growth conditions from the anaerobic to aerobic culture"
- term:
    id: GO:0045454
    label: cell redox homeostasis
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      BCP participates in maintaining cellular redox balance through its
      peroxidase activity, cycling between reduced and oxidized states via
      the thioredoxin system. The unusually high redox potential (-146 mV)
      and ability to use multiple electron donors (Trx1, Trx2, Grx1, Grx3)
      suggest BCP integrates with the broader cellular redox network.
    action: KEEP_AS_NON_CORE
    reason: >-
      While BCP does cycle through the thioredoxin/glutaredoxin redox systems,
      its primary evolved function is peroxide detoxification rather than
      general redox homeostasis. This annotation is technically correct but
      secondary to the core peroxidase function.
    supported_by:
    - reference_id: PMID:21910476
      supporting_text: "BCP can utilize a variety of reducing substrates, including Trx1, Trx2, Grx1, and Grx3"
    - reference_id: PMID:21910476
      supporting_text: "BCP exhibited a high redox potential of -145.9 ± 3.2 mV, the highest to date observed for a Prx"
    - reference_id: file:ECOLI/bcp/bcp-deep-research-falcon.md
      supporting_text: |-
        Bcp can also use Trx2 and glutaredoxins Grx1 and Grx3 as alternative reducing partners, indicating relaxed reductant specificity.
- term:
    id: GO:0016209
    label: antioxidant activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: >-
      BCP is indeed an antioxidant enzyme that detoxifies reactive oxygen
      species. This IEA annotation from InterPro (IPR000866, AhpC/TSA domain)
      is correct but very general. The more specific annotations for
      thioredoxin peroxidase activity (GO:0008379) and thioredoxin-dependent
      peroxiredoxin activity (GO:0140824) provide better functional resolution.
    action: KEEP_AS_NON_CORE
    reason: >-
      Correct but too general. The specific peroxidase activity terms
      (GO:0008379, GO:0140824) are more informative for describing BCP function.
      Retained as a broad parent annotation from InterPro2GO.
- term:
    id: GO:0016491
    label: oxidoreductase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: >-
      BCP is an oxidoreductase (EC 1.11.1.24). This IEA annotation from
      InterPro is correct but extremely general. It is fully subsumed by
      the more specific thioredoxin peroxidase activity annotations. The
      falcon deep research confirms the precise activity (atypical 2-Cys
      peroxiredoxin reducing peroxides), making this grandparent term
      redundant for curation purposes.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Uninformatively broad grandparent term, fully subsumed by the specific
      molecular function annotations (GO:0008379, GO:0140824) that capture the
      experimentally characterized thioredoxin-dependent peroxidase reaction.
      This IEA term adds no curation value beyond the specific peroxidase terms.
    supported_by:
    - reference_id: file:ECOLI/bcp/bcp-deep-research-falcon.md
      supporting_text: |-
        classification as an **atypical 2-Cys peroxiredoxin** with a **Cp–Cr** motif
- term:
    id: GO:0098869
    label: cellular oxidant detoxification
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: >-
      BCP detoxifies cellular oxidants (H2O2 and organic hydroperoxides) by
      reducing them to water and alcohols. This is a core biological process
      annotation that accurately describes BCP function. The combined IEA
      annotation derives from the molecular function annotations (GO:0008379,
      GO:0016209, GO:0140824).
    action: ACCEPT
    reason: >-
      Cellular oxidant detoxification is a core biological function of BCP.
      The bcp null mutant shows hypersensitivity to H2O2, t-butyl hydroperoxide,
      and linoleic acid hydroperoxide, directly demonstrating BCP detoxifies
      these oxidants.
    supported_by:
    - reference_id: PMID:10644761
      supporting_text: "Bcp null mutant grew more slowly than its wild type in aerobic culture and showed the hypersensitivity toward various oxidants such as H(2)O(2), t-butyl hydroperoxide, and linoleic acid hydroperoxide"
- term:
    id: GO:0140824
    label: thioredoxin-dependent peroxiredoxin activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: >-
      GO:0140824 corresponds to EC 1.11.1.24 and represents the specific
      catalytic reaction: hydroperoxide + [thioredoxin]-dithiol = alcohol +
      [thioredoxin]-disulfide + H2O. This is the most precise molecular
      function term for BCP and directly matches the experimentally
      characterized activity.
    action: ACCEPT
    reason: >-
      This is the most specific and accurate MF term for BCP. EC 1.11.1.24
      is assigned to BCP with experimental evidence (PMID:10644761,
      PMID:21910476). BCP uses the thioredoxin system as its primary electron
      donor, making this the correct EC-linked GO term.
    supported_by:
    - reference_id: PMID:10644761
      supporting_text: "BCP showed a thioredoxin-dependent thiol peroxidase activity"
    - reference_id: PMID:21910476
      supporting_text: "Kinetic and thermodynamic features reveal that Escherichia coli BCP is an unusually versatile peroxiredoxin"
    - reference_id: file:ECOLI/bcp/bcp-deep-research-bioreason-sft.md
      supporting_text: "domain logic directly yields the molecular functions formalized as GO:0008379 thioredoxin peroxidase activity"
    - reference_id: file:ECOLI/bcp/bcp-deep-research-falcon.md
      supporting_text: |-
        classification as an **atypical 2-Cys peroxiredoxin** with a **Cp–Cr** motif
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IDA
  original_reference_id: PMID:15911532
  review:
    summary: >-
      Lopez-Campistrous et al. (2005) identified BCP in the cytosolic fraction
      of E. coli K-12 by 2D-gel electrophoresis and tandem mass spectrometry
      after biochemical fractionation. This is direct experimental evidence
      for cytosolic localization.
    action: ACCEPT
    reason: >-
      Direct identification of BCP in the cytosolic fraction by biochemical
      fractionation followed by 2D-gel/MS/MS. BCP lacks signal peptides and
      transmembrane domains, consistent with soluble cytosolic localization.
    supported_by:
    - reference_id: PMID:15911532
      supporting_text: "a proteomic analysis of Escherichia coli in which 3,199 protein forms were detected, and of those 2,160 were annotated and assigned to the cytosol, periplasm, inner membrane, and outer membrane"
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IDA
  original_reference_id: PMID:18304323
  review:
    summary: >-
      Ishihama et al. (2008) independently identified BCP in the cytosolic
      fraction of E. coli MC4100 by LC-MS/MS. This provides independent
      confirmation of cytosolic localization from a second proteomics study.
    action: ACCEPT
    reason: >-
      Independent confirmation of cytosolic localization using LC-MS/MS on
      the cytosolic fraction. Consistent with the other IDA annotation from
      PMID:15911532 and with the absence of signal peptide or transmembrane
      domains.
    supported_by:
    - reference_id: PMID:18304323
      supporting_text: "we identified 1103 proteins from the cytosolic fraction of the Escherichia coli strain MC4100"
- term:
    id: GO:0006979
    label: response to oxidative stress
  evidence_type: IMP
  original_reference_id: PMID:10644761
  review:
    summary: >-
      The bcp null mutant showed clear hypersensitivity to oxidative stress:
      slower growth in aerobic culture and increased sensitivity to H2O2,
      t-butyl hydroperoxide, and linoleic acid hydroperoxide. BCP expression
      was induced 3-fold upon shift from anaerobic to aerobic conditions.
      Complementation with bcp gene restored resistance. This is strong
      IMP (mutant phenotype) evidence.
    action: ACCEPT
    reason: >-
      Strong mutant phenotype evidence. The bcp null mutant has clear
      oxidative stress hypersensitivity that is complemented by bcp
      expression, directly demonstrating BCP participates in the response
      to oxidative stress.
    supported_by:
    - reference_id: PMID:10644761
      supporting_text: "Bcp null mutant grew more slowly than its wild type in aerobic culture and showed the hypersensitivity toward various oxidants such as H(2)O(2), t-butyl hydroperoxide, and linoleic acid hydroperoxide"
    - reference_id: PMID:10644761
      supporting_text: "The peroxide hypersensitivity of the null mutant could be complemented by the expression of bcp gene"
- term:
    id: GO:0008379
    label: thioredoxin peroxidase activity
  evidence_type: IDA
  original_reference_id: PMID:10644761
  review:
    summary: >-
      Jeong et al. (2000) directly demonstrated thioredoxin-dependent
      peroxidase activity of purified recombinant BCP. BCP reduced H2O2,
      t-butyl hydroperoxide, and linoleic acid hydroperoxide using
      thioredoxin as electron donor. The C45S mutation abolished activity,
      confirming Cys-45 as the catalytic peroxidatic cysteine.
    action: ACCEPT
    reason: >-
      Direct biochemical demonstration of thioredoxin-dependent peroxidase
      activity using purified protein and multiple peroxide substrates. This
      is the primary IDA evidence establishing BCP as a thiol-specific
      peroxidase and the core molecular function of the protein.
    supported_by:
    - reference_id: PMID:10644761
      supporting_text: "BCP showed a thioredoxin-dependent thiol peroxidase activity"
    - reference_id: PMID:10644761
      supporting_text: "Replacement of Cys-45 with serine resulted in the complete loss of thiol peroxidase activity"
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:10644761
  title: >-
    Thioredoxin-dependent hydroperoxide peroxidase activity of bacterioferritin
    comigratory protein (BCP) as a new member of the thiol-specific antioxidant
    protein (TSA)/Alkyl hydroperoxide peroxidase C (AhpC) family.
  findings:
  - statement: >-
      BCP is a thioredoxin-dependent thiol peroxidase that reduces H2O2 and
      organic hydroperoxides. Cys-45 is the essential catalytic residue.
    supporting_text: >-
      BCP showed a thioredoxin-dependent thiol peroxidase activity...Replacement
      of Cys-45 with serine resulted in the complete loss of thiol peroxidase
      activity
  - statement: >-
      BCP preferentially reduces linoleic acid hydroperoxide over H2O2 and
      t-butyl hydroperoxide when using thioredoxin as electron donor.
    supporting_text: >-
      BCP preferentially reduced linoleic acid hydroperoxide rather than
      H(2)O(2) and t-butyl hydroperoxide with the use of thioredoxin as an
      in vivo immediate electron donor
  - statement: >-
      BCP exists as a monomer and its functional Cys-45 exists as cysteine
      sulfenic acid intermediate during catalysis.
    supporting_text: >-
      BCP exists as a monomer, and its functional Cys-45 appeared to exist as
      cysteine sulfenic acid
  - statement: >-
      BCP expression is induced by oxidative stress and the bcp null mutant
      is hypersensitive to oxidants.
    supporting_text: >-
      BCP was induced 3-fold by the oxidative stress given by changing the
      growth conditions from the anaerobic to aerobic culture. Bcp null mutant
      grew more slowly than its wild type in aerobic culture and showed the
      hypersensitivity toward various oxidants
- id: PMID:15911532
  title: >-
    Localization, annotation, and comparison of the Escherichia coli K-12 proteome
    under two states of growth.
  findings:
  - statement: BCP was identified in the cytosolic fraction of E. coli K-12.
    supporting_text: >-
      a proteomic analysis of Escherichia coli in which 3,199 protein forms
      were detected, and of those 2,160 were annotated and assigned to the
      cytosol, periplasm, inner membrane, and outer membrane
- id: PMID:18304323
  title: Protein abundance profiling of the Escherichia coli cytosol.
  findings:
  - statement: >-
      BCP was identified among 1103 proteins in the E. coli cytosolic fraction,
      independently confirming cytosolic localization.
    supporting_text: >-
      we identified 1103 proteins from the cytosolic fraction of the
      Escherichia coli strain MC4100
- id: PMID:21910476
  title: >-
    Kinetic and thermodynamic features reveal that Escherichia coli BCP is an
    unusually versatile peroxiredoxin.
  findings:
  - statement: >-
      BCP is a monomer by analytical ultracentrifugation and has broad substrate
      specificity, using multiple reducing substrates (Trx1, Trx2, Grx1, Grx3).
    supporting_text: >-
      both oxidized and reduced E. coli BCP behave as monomers in solution...BCP
      can utilize a variety of reducing substrates, including Trx1, Trx2, Grx1,
      and Grx3
  - statement: >-
      BCP has the highest redox potential (-146 mV) of any characterized
      peroxiredoxin, suggesting it remains active under highly oxidizing conditions.
    supporting_text: >-
      BCP exhibited a high redox potential of -145.9 ± 3.2 mV, the highest to
      date observed for a Prx
  - statement: >-
      BCP shows broad peroxide specificity with comparable rates for H2O2 and
      cumene hydroperoxide, and a pKa of ~5.8 for the peroxidatic Cys45.
    supporting_text: >-
      BCP exhibited a broad peroxide specificity, with comparable rates for
      H(2)O(2) and cumene hydroperoxide...a pK(a) of ~5.8 for the peroxidatic
      cysteine (Cys45)
- id: PMID:19298085
  title: >-
    Interrogating the molecular details of the peroxiredoxin activity of the
    Escherichia coli bacterioferritin comigratory protein using high-resolution
    mass spectrometry.
  findings:
  - statement: >-
      BCP is an atypical 2-Cys peroxiredoxin that forms an intramolecular
      disulfide between Cys-45 and Cys-50 during catalysis.
    supporting_text: >-
      A transient sulfenic acid is initially formed on Cys-45, before resolution
      by the formation of an intramolecular disulfide bond between Cys-45 and
      Cys-50
  - statement: >-
      The C50S mutant adopts an alternative mechanism forming an intermolecular
      disulfide between two BCP molecules.
    supporting_text: >-
      The C50S BCP mutant reacts with peroxide to form a sulfenic acid on Cys-45...
      resulting in a dimeric intermediate containing an intermolecular disulfide bond
- id: PMID:20078128
  title: >-
    Subdivision of the bacterioferritin comigratory protein family of bacterial
    peroxiredoxins based on catalytic activity.
  findings:
  - statement: >-
      The BCP family is subdivided into atypical 2-Cys (like E. coli BCP) and
      1-Cys classes based on catalytic mechanism.
    supporting_text: >-
      These studies support the subdivision of the BCP family of peroxiredoxins
      into two classes based on their catalytic activity
- id: file:ECOLI/bcp/bcp-deep-research-bioreason-sft.md
  title: BioReason-Pro SFT deep research for bcp
  findings:
  - statement: >-
      Domain architecture analysis correctly identifies the thioredoxin-like
      scaffold harboring peroxiredoxin-specific catalytic signatures,
      supporting thiol-based peroxidase function.
- id: file:ECOLI/bcp/bcp-deep-research-falcon.md
  title: >-
    Falcon (Edison Scientific) deep research report for E. coli bcp (P0AE52):
    Peroxiredoxin Bcp/PrxQ functional annotation
  findings:
  - statement: >-
      BCP is an atypical 2-Cys peroxiredoxin with a CPXXXXCR active-site motif;
      Cys45 is the peroxidatic cysteine and Cys50 the resolving cysteine.
    reference_section_type: OTHER
    supporting_text: |-
      Cys45 is the peroxidatic cysteine (Cp) and Cys50 is the resolving cysteine (Cr); Cys99 is present but not the primary catalytic thiol. C45S abolishes detectable Trx-dependent peroxidase/antioxidant activity.
  - statement: >-
      Later kinetic work established broad peroxide substrate specificity for
      BCP, supporting its description as an unusually versatile peroxiredoxin.
    reference_section_type: OTHER
    supporting_text: |-
      later kinetic work showed broad peroxide specificity, with comparable rates for H2O2 and cumene hydroperoxide under some assay conditions
  - statement: >-
      BCP has relaxed reductant specificity, accepting electrons from
      thioredoxins (Trx1, Trx2) and glutaredoxins (Grx1, Grx3).
    reference_section_type: OTHER
    supporting_text: |-
      Bcp can also use Trx2 and glutaredoxins Grx1 and Grx3 as alternative reducing partners, indicating relaxed reductant specificity.
  - statement: >-
      BCP is monomeric in solution up to at least 200 uM, consistent with the
      monomeric oligomeric-state annotation.
    reference_section_type: OTHER
    supporting_text: |-
      BCP is reported as **monomeric** in solution up to at least **200 µM**
  - statement: >-
      BCP has an unusually high midpoint redox potential, supporting activity
      under relatively oxidizing intracellular conditions.
    reference_section_type: OTHER
    supporting_text: |-
      relatively **high midpoint potential** for BCP of **−145.9 ± 3.2 mV**
  - statement: >-
      The peroxidatic Cys45 has a low pKa (~5.8), consistent with a reactive
      thiolate at physiological pH.
    reference_section_type: OTHER
    supporting_text: |-
      Peroxidatic Cys45 **pKa ~5.8**, consistent with a reactive thiolate at physiological pH.
  - statement: >-
      A bcp promoter-lacZ fusion showed oxygen-responsive expression, with an
      approximately 3-fold increase in activity under oxygen stress.
    reference_section_type: OTHER
    supporting_text: |-
      approximately **3-fold increase** in β-galactosidase activity under oxygen stress
  - statement: >-
      Cytosolic localization of E. coli BCP is the best-supported annotation but
      remains an inference; no direct localization experiment was found in the
      retrieved literature.
    reference_section_type: OTHER
    supporting_text: |-
      best-supported annotation is cytosolic localization, but this remains inference rather than direct localization evidence
core_functions:
- description: >-
    BCP catalyzes the thioredoxin-dependent reduction of hydrogen peroxide
    and organic hydroperoxides (including linoleic acid hydroperoxide) to
    water and the corresponding alcohols. This is its primary evolved
    molecular function, operating through an atypical 2-Cys peroxiredoxin
    mechanism (Cys45-SOH intermediate, Cys45-Cys50 intramolecular disulfide,
    thioredoxin-mediated reduction).
  molecular_function:
    id: GO:0140824
    label: thioredoxin-dependent peroxiredoxin activity
  directly_involved_in:
  - id: GO:0098869
    label: cellular oxidant detoxification
  locations:
  - id: GO:0005829
    label: cytosol
  supported_by:
  - reference_id: PMID:10644761
    supporting_text: "BCP showed a thioredoxin-dependent thiol peroxidase activity"
  - reference_id: PMID:21910476
    supporting_text: "Kinetic and thermodynamic features reveal that Escherichia coli BCP is an unusually versatile peroxiredoxin"
  - reference_id: PMID:19298085
    supporting_text: "catalysis occurs via an atypical two-cysteine peroxiredoxin pathway"
- description: >-
    BCP protects the cell against oxidative stress by detoxifying peroxides.
    The bcp null mutant is hypersensitive to H2O2, t-butyl hydroperoxide,
    and linoleic acid hydroperoxide, and grows more slowly under aerobic
    conditions. BCP expression is induced 3-fold upon shift from anaerobic
    to aerobic growth.
  molecular_function:
    id: GO:0008379
    label: thioredoxin peroxidase activity
  directly_involved_in:
  - id: GO:0006979
    label: response to oxidative stress
  locations:
  - id: GO:0005829
    label: cytosol
  supported_by:
  - reference_id: PMID:10644761
    supporting_text: "Bcp null mutant grew more slowly than its wild type in aerobic culture and showed the hypersensitivity toward various oxidants"
  - reference_id: PMID:10644761
    supporting_text: "BCP was induced 3-fold by the oxidative stress given by changing the growth conditions from the anaerobic to aerobic culture"
suggested_questions:
- question: >-
    What are the relative contributions of BCP, AhpC, and Tpx to peroxide
    detoxification in E. coli under different stress conditions?
  experts:
  - Poole LB
- question: >-
    Does BCP have a signaling role in E. coli (as suggested by UniProt
    description of H2O2 sensor function), or is its role purely detoxification?
  experts:
  - Poole LB
  - Kim IH
suggested_experiments:
- hypothesis: >-
    BCP serves as a "last resort" peroxidase under severe oxidative stress
    when AhpC is inactivated by overoxidation.
  description: >-
    Compare peroxide sensitivity and survival of wild-type, bcp-null,
    ahpC-null, and bcp/ahpC double mutant E. coli under increasing
    concentrations of H2O2 and organic hydroperoxides. Measure the oxidation
    state of BCP and AhpC under progressive oxidative stress to determine
    if BCP remains active when AhpC is overoxidized.
  experiment_type: genetic epistasis / redox proteomics