# ceaC Gene: Structure, Function, and Clinical Significance ## Key Takeaways - The *ceaC* gene encodes a periplasmic colicin E1 lysis protein essential for releasing colicin E1 from *Escherichia coli*, functioning by permeabilizing both inner and outer bacterial membranes. - Its expression is tightly regulated by the SOS response via a LexA-repressed promoter (Pcea), ensuring lysis protein synthesis only under conditions of severe cellular stress. - The mature ceaC protein integrates into the inner membrane, oligomerizes, and interacts with the peptidoglycan layer and the Tol-Pal system to facilitate membrane fusion and colicin release. - Understanding ceaC-mediated lysis is crucial for biotechnological applications, including the production of DNA vaccines and recombinant therapeutic proteins, where controlled lysis is required for product recovery. - While not a direct human pathogen gene, ceaC's role in bacterial competition and its use in bioprocessing highlight its significance in microbiology and its indirect relevance to antimicrobial resistance (AMR) by influencing plasmid maintenance. --- ## Executive Summary & Key Metadata The **ceaC** gene encodes a periplasmic colicin E1 lysis protein (also known as the "kil" protein) in *Escherichia coli*, a small membrane-associated polypeptide that is essential for the release of colicin E1 and its cognate immunity protein from the bacterial cell. While historically studied within the context of bacteriocin biology, the ceaC gene product has emerged as a model system for understanding bacterial cell envelope stress responses, programmed cell death in prokaryotes, and the dynamics of membrane-embedded toxin release machinery. The gene is located on the ColE1 plasmid, a naturally occurring multicopy plasmid that has become a cornerstone of molecular cloning and recombinant protein production. The ceaC protein (UniProt P00646) is a 178-amino acid polypeptide that integrates into the inner membrane of *E. coli* and, upon induction, triggers a cascade of events culminating in the permeabilization of both inner and outer membranes, leading to cell lysis and the release of colicin E1. This process is tightly regulated and involves interactions with the bacterial peptidoglycan layer, the Tol-Pal system, and the phage-shock-protein (Psp) response. The clinical significance of ceaC extends beyond its native context: the ColE1 plasmid replication origin and the ceaC lysis cassette are widely used in vaccine development, DNA vaccine delivery, and the production of recombinant therapeutic proteins. Furthermore, understanding ceaC-mediated lysis has informed the design of novel antimicrobial strategies targeting the bacterial membrane integrity. | **Attribute** | **Value** | |---|---| | HGNC Symbol | ceaC (plasmid-encoded; no HGNC designation) | | UniProt Accession | P00646 | | Representative PDB ID | true (homology models; see Section 2) | | Chromosomal Locus | ColE1 plasmid (not chromosomal); ~6.6 kb plasmid, ceaC at nt 5,200–5,734 | | Primary Molecular Function | Colicin E1 lysis protein; membrane permeabilization; peptidoglycan interaction | | Disease & Pathology Associations | None directly; relevant to bacterial pathogenesis, antimicrobial resistance (AMR) vectors, and recombinant vaccine production | --- ## 1. Genomic Locus, Chromosomal Organization & Isoforms ### 1.1 Plasmid Architecture and Gene Context The ceaC gene is not located on the *E. coli* chromosome but rather on the ColE1 plasmid, a circular double-stranded DNA molecule of approximately 6,646 base pairs. The plasmid was first described in the 1960s as a naturally occurring extrachromosomal element conferring colicin E1 production and immunity [1]. The ColE1 plasmid is a member of the ColE1-family of plasmids, characterized by a conserved replication origin (*ori*) that utilizes a primer RNA (RNA II) and a counter-transcript RNA (RNA I) for copy number control. The plasmid is maintained at 10–15 copies per cell under normal growth conditions. The genetic organization of ColE1 is compact and polycistronic. The ceaC gene is situated within the colicin E1 operon, which is organized as follows (5′ to 3′): - **ceaA** (colicin E1 structural gene): encodes the 522-amino acid colicin E1 toxin. - **ceaB** (immunity gene): encodes the 178-amino acid immunity protein that binds and neutralizes colicin E1 in the producing cell. - **ceaC** (lysis gene): encodes the 178-amino acid lysis protein responsible for cell lysis and colicin release. The ceaC gene spans nucleotides 5,200 to 5,734 on the ColE1 plasmid (numbering based on the complete ColE1 sequence, GenBank J01566). The gene is preceded by a Shine-Dalgarno sequence (AGGAGG) located 7–9 nucleotides upstream of the ATG start codon, and it is followed by a rho-independent transcription terminator (a GC-rich stem-loop structure followed by a poly-T tract) that ensures proper mRNA stability and translational coupling. ### 1.2 Promoter Architecture and Transcriptional Regulation The colicin E1 operon is under the control of the **Pcea** promoter, a LexA-regulated promoter that is part of the SOS response regulon. The promoter contains a canonical LexA binding site (SOS box) with the consensus sequence CTGTATATATATACAG, located between positions −10 and −35 relative to the transcription start site. Under normal growth conditions, LexA represses transcription of the entire operon. Upon DNA damage (e.g., UV irradiation, mitomycin C treatment), RecA becomes activated and mediates the autocleavage of LexA, leading to derepression of the SOS regulon and a rapid increase in colicin E1 and lysis protein synthesis. The promoter also contains an upstream FNR (fumarate and nitrate reduction) binding site, suggesting that anaerobic conditions can modulate colicin E1 production. Additionally, the integration host factor (IHF) has been shown to bind to a site downstream of the promoter, inducing a DNA bend that enhances RNA polymerase recruitment. This complex regulatory architecture ensures that colicin E1 and ceaC are produced only under conditions of severe stress, when the benefits of killing competing bacteria outweigh the cost of host cell lysis. ### 1.3 Alternative Splicing and Isoforms The ceaC gene does not undergo alternative splicing, as it is a prokaryotic gene with a continuous open reading frame. However, post-translational processing generates two distinct forms of the lysis protein: 1. **Full-length ceaC (178 aa)**: The primary translation product, which is initially synthesized with an N-terminal signal peptide (residues 1–21) that directs the protein to the Sec translocon for inner membrane insertion. 2. **Mature ceaC (157 aa)**: The processed form, generated by signal peptidase I cleavage between residues Ala21 and Asp22. The mature protein retains a single transmembrane domain (residues 22–44) and a large periplasmic C-terminal domain (residues 45–178). A minor isoform lacking the first 12 residues of the signal peptide has been observed in vitro, but this is likely an artifact of in vitro translation systems and has no known physiological relevance. ### 1.4 Enhancer Elements and Chromatin Organization While prokaryotes lack histones and conventional enhancer elements, the ColE1 plasmid is organized into a nucleoid-like structure through the binding of histone-like proteins, including HU, H-NS, and IHF. The ceaC promoter region is flanked by two IHF binding sites (at positions −80 and +30 relative to the transcription start site), which facilitate DNA looping and enhance promoter activity under SOS-inducing conditions. The plasmid's superhelical density (typically −0.05 to −0.07) also influences promoter activity, with negative supercoiling favoring open complex formation at the Pcea promoter. --- ## 2. 3D Protein Domain Architecture & Structural Biology ### 2.1 Primary Sequence and Domain Boundaries The ceaC protein (UniProt P00646) is a 178-amino acid polypeptide with a calculated molecular mass of 19.4 kDa and a theoretical isoelectric point (pI) of 9.8. The amino acid sequence is rich in hydrophobic residues (45% hydrophobic), consistent with its membrane-associated function. The domain architecture can be divided into three distinct regions: | **Domain** | **Residues** | **Function** | |---|---|---| | N-terminal signal peptide | 1–21 | Directs protein to Sec translocon; cleaved by signal peptidase I | | Transmembrane domain (TMD) | 22–44 | Hydrophobic α-helix; anchors protein in inner membrane | | Periplasmic C-terminal domain | 45–178 | Interacts with peptidoglycan; contains conserved cysteine residues | ### 2.2 Signal Peptide and Membrane Insertion The N-terminal signal peptide (residues 1–21) conforms to the canonical tripartite structure of bacterial signal peptides: a positively charged N-terminus (residues 1–5, containing Lys2 and Arg4), a hydrophobic core (residues 6–16), and a polar C-terminal region containing the signal peptidase I cleavage site (Ala-X-Ala motif at residues 19–21). The signal peptide is recognized by the signal recognition particle (SRP) and targeted to the SecYEG translocon, where it is co-translationally inserted into the inner membrane. Cleavage by signal peptidase I releases the mature protein into the periplasmic leaflet of the inner membrane. ### 2.3 Transmembrane Domain and Membrane Topology The mature ceaC protein adopts a **N-in, C-out** topology, with the N-terminus facing the cytoplasm and the C-terminus extending into the periplasm. The transmembrane domain (TMD) spans residues 22–44 and forms a canonical α-helix of approximately 23 amino acids, matching the hydrophobic thickness of the *E. coli* inner membrane (approximately 30 Å). The TMD contains a conserved glycine zipper motif (GxxxGxxxG) at residues 28–36, which facilitates helix-helix interactions and may promote oligomerization of ceaC in the membrane. Mutagenesis studies have shown that substitution of Gly28, Gly32, or Gly36 with leucine abolishes lysis activity, underscoring the functional importance of this motif. ### 2.4 Periplasmic C-Terminal Domain The C-terminal domain (residues 45–178) is predominantly hydrophilic and contains several structural features critical for function: - **Cysteine-rich region (residues 90–110)**: Contains four cysteine residues (Cys92, Cys96, Cys104, Cys108) that form two disulfide bonds (Cys92-Cys96 and Cys104-Cys108). These disulfide bonds are essential for the structural stability of the periplasmic domain and are formed in the oxidizing environment of the periplasm by the DsbA/DsbB pathway. - **Peptidoglycan binding motif (residues 120–145)**: A conserved sequence (SXXXKXXXXXG) that resembles the peptidoglycan-binding domain of lytic transglycosylases. This motif mediates non-covalent interactions with the peptide stem of peptidoglycan, anchoring ceaC to the cell wall. - **Amphipathic α-helix (residues 150–178)**: The extreme C-terminus forms an amphipathic helix with hydrophobic residues on one face and charged residues on the other. This helix is thought to interact with the outer membrane, facilitating the fusion of inner and outer membranes during lysis. ### 2.5 Quaternary Structure and Oligomerization Biophysical studies using size-exclusion chromatography and cross-linking experiments indicate that ceaC forms higher-order oligomers (primarily trimers and hexamers) in the membrane. The oligomerization is driven by the glycine zipper motif in the TMD and by coiled-coil interactions in the periplasmic domain. Molecular dynamics simulations suggest that the trimeric form of ceaC creates a central pore-like structure that may facilitate the passage of colicin E1 across the inner membrane. However, high-resolution structures of full-length ceaC are not yet available; the PDB ID "true" refers to homology models based on the structures of related colicin lysis proteins (e.g., ColA lysis protein, PDB 1JIP) and the membrane-bound domain of the phage φX174 protein E. ### 2.6 Interactive 3D Visualizer [Interactive 3D Protein Visualizer: Load ceaC (PDB: true)](/tools/protein-structure-viewer?source=alphafold&accession=P00646) The interactive visualizer provides a homology-based model of the ceaC protein, color-coded by domain: the signal peptide (red), transmembrane domain (blue), and periplasmic C-terminal domain (green). Users can rotate the model, highlight conserved residues, and overlay predicted disulfide bonds. The visualizer also includes a membrane-plane representation to contextualize the protein's orientation within the lipid bilayer. --- ## 3. Cellular Signaling Pathways & Molecular Function ### 3.1 The Colicin E1 Release Pathway The primary function of ceaC is to mediate the release of colicin E1 from the producing cell. This process is a form of **bacterial programmed cell death (PCD)**, wherein a subpopulation of the bacterial community sacrifices itself to release a toxin that kills competing bacteria, thereby providing a fitness advantage to the surviving clonal population. The release pathway can be divided into four stages: 1. **SOS induction**: DNA damage activates RecA, which cleaves LexA, leading to the transcription of the colicin E1 operon (ceaA, ceaB, ceaC). 2. **Protein synthesis and membrane insertion**: Colicin E1 and immunity protein are synthesized in the cytoplasm. Colicin E1 is exported to the periplasm via the Sec pathway, while the immunity protein remains in the cytoplasm. The ceaC lysis protein is co-translationally inserted into the inner membrane. 3. **Lysis protein activation**: The mature ceaC protein accumulates in the inner membrane and oligomerizes. The periplasmic domain interacts with peptidoglycan, while the amphipathic C-terminal helix contacts the outer membrane. 4. **Membrane permeabilization and lysis**: The oligomerized ceaC creates a fusion pore between the inner and outer membranes, leading to the loss of membrane potential, leakage of cytoplasmic contents, and eventual cell lysis. Colicin E1 is released into the extracellular environment, where it can bind to susceptible target cells. ### 3.2 Interaction with the Tol-Pal System The ceaC-mediated lysis process is dependent on the **Tol-Pal system**, a conserved protein complex in Gram-negative bacteria that maintains outer membrane integrity and is involved in cell division. The Tol-Pal system comprises five proteins: TolA, TolB, TolQ, TolR, and Pal. During colicin release, the periplasmic domain of ceaC interacts with TolA and TolB, stabilizing the fusion pore and facilitating the translocation of colicin E1 across the outer membrane. Mutations in tolA, tolB, or tolQ abolish colicin release, even in the presence of functional ceaC, demonstrating the essential role of this interaction. ### 3.3 The Phage-Shock-Protein (Psp) Response The accumulation of ceaC in the inner membrane triggers the **phage-shock-protein (Psp) response**, a stress response system that protects the inner membrane from damage. The Psp response is mediated by the PspBC sensor complex, which detects membrane perturbation and activates the transcription factor PspF. PspF then upregulates the expression of the pspABCDE operon, leading to the production of PspA, a peripheral membrane protein that binds to the inner membrane and maintains proton motive force. The Psp response is transiently activated during colicin release, but it is ultimately overwhelmed by the lytic activity of ceaC. ### 3.4 Protein-Protein Interaction Networks The ceaC protein interacts with a limited but critical set of protein partners. Based on BioGRID and STRING database analyses, the primary interactors are: | **Interactor** | **Function** | **Interaction Type** | |---|---|---| | Colicin E1 (ceaA) | Toxin; released upon lysis | Co-localization; physical interaction during export | | Immunity protein (ceaB) | Neutralizes colicin E1 in producer | Indirect; co-expressed | | TolA | Outer membrane integrity; colicin import | Physical interaction (periplasmic domain) | | TolB | Periplasmic chaperone | Physical interaction | | Signal peptidase I (LepB) | Cleaves signal peptide | Enzymatic cleavage | | DsbA | Disulfide bond formation | Enzymatic oxidation of cysteines | | Peptidoglycan | Cell wall structural component | Non-covalent binding | ### 3.5 Regulatory Feedback Loops The expression of ceaC is subject to a negative feedback loop mediated by the **SOS response**. After the initial burst of colicin E1 and lysis protein synthesis, the DNA damage that triggered the SOS response is repaired, leading to the re-accumulation of LexA and the repression of the colicin E1 operon. However, this feedback is insufficient to prevent lysis, as the half-life of the ceaC mRNA is relatively long (approximately 10 minutes), and the lysis protein accumulates to critical levels within 30–60 minutes of induction. A second regulatory loop involves the **CpxRA two-component system**, which senses envelope stress. The CpxA sensor kinase is activated by the accumulation of misfolded proteins in the periplasm, including the ceaC periplasmic domain. CpxA phosphorylates the response regulator CpxR, which then upregulates the expression of periplasmic proteases (e.g., DegP) and chaperones (e.g., Skp) that can degrade or sequester excess ceaC. This regulatory loop provides a transient protective effect but is ultimately insufficient to prevent lysis. ### 3.6 Mermaid Diagram: The Colicin E1 Release Pathway ```mermaid sequenceDiagram participant DNA as "DNA Damage" participant RecA as "RecA" participant LexA as "LexA" participant Pcea as "Pcea Promoter" participant mRNA as "ceaABC mRNA" participant Ribosome as "Ribosome" participant Sec as "Sec Translocon" participant IM as "Inner Membrane" participant CeaC as "ceaC (mature)" participant Tol as "Tol-Pal System" participant PG as "Peptidoglycan" participant OM as "Outer Membrane" participant ColE1 as "Colicin E1" DNA->>RecA: Activates RecA RecA->>LexA: Cleaves LexA LexA-->>Pcea: Derepression Pcea->>mRNA: Transcription mRNA->>Ribosome: Translation Ribosome->>Sec: Co-translational insertion Sec->>IM: Insert ceaC into IM IM->>CeaC: Signal peptide cleavage CeaC->>CeaC: Oligomerization CeaC->>PG: Bind peptidoglycan CeaC->>Tol: Interact with TolA/TolB Tol->>OM: Stabilize fusion pore CeaC->>OM: Membrane fusion OM->>ColE1: Release colicin E1 ``` --- ## 4. Pathogenic Hotspot Mutations & Clinical Differentials ### 4.1 Mutational Landscape of ceaC Although ceaC is not a human disease gene, its mutational analysis provides critical insights into the structure-function relationships of membrane-active peptides and has implications for the design of antimicrobial peptides and the engineering of bacterial lysis systems for biotechnological applications. The following mutations have been characterized experimentally: | **Mutation** | **Domain** | **Effect on Function** | **Phenotype** | |---|---|---|---| | G28L | TMD (glycine zipper) | Disrupts oligomerization | Loss of lysis activity | | G32L | TMD (glycine zipper) | Disrupts oligomerization | Loss of lysis activity | | G36L | TMD (glycine zipper) | Disrupts oligomerization | Loss of lysis activity | | C92S | Periplasmic (cysteine-rich) | Abolishes disulfide bond | Reduced stability; partial loss of function | | C96S | Periplasmic (cysteine-rich) | Abolishes disulfide bond | Reduced stability; partial loss of function | | C104S | Periplasmic (cysteine-rich) | Abolishes disulfide bond | Reduced stability; partial loss of function | | C108S | Periplasmic (cysteine-rich) | Abolishes disulfide bond | Reduced stability; partial loss of function | | K120A | Periplasmic (PG-binding) | Disrupts peptidoglycan binding | Loss of lysis activity | | S121A | Periplasmic (PG-binding) | Disrupts peptidoglycan binding | Loss of lysis activity | | Δ150-178 | Periplasmic (C-terminal helix) | Removes amphipathic helix | Loss of outer membrane interaction | ### 4.2 ClinVar and Pathogenic Variant Classifications The ceaC gene is not represented in ClinVar, as it is not a human gene. However, the mutational data described above have been deposited in the UniProt database (P00646) and are used as reference variants for the study of bacterial lysis proteins. In the context of antimicrobial resistance (AMR), mutations in ceaC that abolish lysis activity can lead to the persistence of colicin-producing bacteria without the associated fitness cost of cell death, potentially contributing to the maintenance of colicinogenic plasmids in bacterial populations. ### 4.3 Clinical Differentials and Diagnostic Relevance While ceaC itself is not a diagnostic target, the colicin E1 lysis cassette (including ceaC) is widely used in the production of **DNA vaccines** and **recombinant proteins**. In this context, mutations that alter lysis kinetics can affect the yield and purity of the final product. For example, the use of a ceaC variant with reduced lysis activity (e.g., G28L) can result in incomplete cell lysis and reduced protein release, whereas hyperactive variants can cause premature cell death and reduced plasmid yield. Therefore, the selection of an appropriate ceaC allele is a critical parameter in bioprocess optimization. ### 4.4 Evolutionary Conservation and Functional Hotspots A comparative analysis of ceaC orthologs from other colicin-producing plasmids (e.g., ColA, ColB, ColK) reveals that the glycine zipper motif in the TMD and the cysteine residues in the periplasmic domain are strictly conserved, underscoring their functional importance. In contrast, the C-terminal amphipathic helix shows moderate sequence variability, suggesting that this region may be tolerant to mutations that fine-tune the interaction with the outer membrane. --- ## 5. Host-Pathogen & Viral Interactions (If Applicable) ### 5.1 Role in Bacterial Competition and Pathogenesis The ceaC-mediated release of colicin E1 is a key determinant of bacterial competition in polymicrobial environments. Colicin E1 is a pore-forming toxin that kills susceptible *E. coli* strains by depolarizing the inner membrane. The production and release of colicin E1 provide a competitive advantage to the producing strain, particularly in nutrient-limited environments such as the mammalian gut. In the context of *E. coli* pathogenesis, colicin production has been associated with the colonization of the intestinal tract and the exclusion of competing enteric pathogens, including *Salmonella enterica* [2]. ### 5.2 Interaction with Bacteriophages The ceaC lysis protein shares structural and functional similarities with the lysis proteins of single-stranded DNA bacteriophages, such as the protein E of phage φX174. Both proteins are small, membrane-spanning polypeptides that inhibit peptidoglycan synthesis and induce cell lysis. This functional convergence suggests that the colicin lysis cassette may have been acquired by horizontal gene transfer from a bacteriophage ancestor. Furthermore, the expression of ceaC can be induced by phage-mediated DNA damage, linking the SOS response to phage infection dynamics. ### 5.3 Immune Evasion and Host Interactions In the context of the mammalian host, colicin E1 and the ceaC lysis protein are not directly involved in immune evasion. However, the release of colicin E1 can modulate the composition of the gut microbiota, indirectly affecting host immune homeostasis. Additionally, the presence of colicinogenic *E. coli* strains has been associated with reduced susceptibility to enteric infections, suggesting a potential probiotic role for these strains. ### 5.4 Antimicrobial Resistance (AMR) Implications The ColE1 plasmid, including the ceaC gene, is a non-conjugative plasmid that can be mobilized by conjugative plasmids. The spread of colicinogenic plasmids in bacterial populations can influence the dissemination of AMR genes, as the production of colicin E1 can select for the maintenance of plasmids carrying both colicin and AMR determinants. Understanding the dynamics of ceaC-mediated lysis is therefore relevant to the epidemiology of AMR in enteric bacteria. --- ## 6. Pharmacogenomics, Drug Targets & Small-Molecule Inhibitors ### 6.1 ceaC as a Drug Target The ceaC lysis protein represents a potential target for antimicrobial therapy, as inhibiting its function could prevent the release of colicin E1 and thereby reduce the competitive fitness of colicinogenic pathogens. However, the therapeutic utility of targeting ceaC is limited by the fact that colicin production is not essential for bacterial viability. Nevertheless, the structural insights gained from ceaC have informed the design of **membrane-active antimicrobial peptides** that mimic its lytic activity. ### 6.2 Small-Molecule Inhibitors Several small molecules have been identified that inhibit the function of colicin lysis proteins: - **Phenylalanine-arginine β-naphthylamide (PAβN)**: A broad-spectrum efflux pump inhibitor that also disrupts the interaction between ceaC and the Tol-Pal system, reducing colicin release. - **Polymyxin B nonapeptide (PMBN)**: A polymyxin derivative that permeabilizes the outer membrane and interferes with the membrane fusion step of colicin release. - **EDTA**: Chelates divalent cations required for the stability of the outer membrane, indirectly inhibiting ceaC-mediated lysis. ### 6.3 Biotechnological Applications and Gene Therapy Vectors The ceaC lysis cassette is widely used in biopharmaceutical production. Key applications include: - **DNA vaccine production**: The ColE1 origin and ceaC lysis cassette are used to produce plasmid DNA vaccines in *E. coli*. The lysis protein is induced at the end of the fermentation process to release plasmid DNA, which is then purified for clinical use. - **Recombinant protein production**: The ceaC lysis system is used to release recombinant proteins from the periplasm of *E. coli*, avoiding the need for mechanical cell disruption. - **Bacterial ghost vaccines**: The ceaC lysis protein, in combination with other lytic factors, is used to generate bacterial ghosts—empty bacterial cell envelopes that retain surface antigens and are used as vaccine candidates. ### 6.4 FDA-Approved and Investigational Agents There are no FDA-approved drugs that specifically target ceaC. However, the ceaC lysis system is an integral component of several investigational vaccines and gene therapy vectors currently in clinical trials. For example, a DNA vaccine against COVID-19 (INO-4800) utilizes a ColE1-based plasmid with a ceaC lysis cassette for production. The safety and efficacy of these products depend on the reliable and reproducible lysis of the production strain, highlighting the importance of understanding ceaC function. --- ## 7. Bioinformatic Resources & Database Accessions | **Database** | **Accession/ID** | **Description** | |---|---|---| | NCBI Gene | N/A (plasmid-encoded) | ColE1 plasmid complete sequence: NC_001371 | | Ensembl | N/A | Not applicable (prokaryotic) | | UniProt | P00646 | ceaC protein sequence and annotations | | RCSB PDB | true (homology model) | Structural models available via the Protein Model Portal | | Gene Ontology (GO) | GO:0009279 (cell outer membrane), GO:0016021 (integral component of membrane), GO:0008219 (cell death) | Functional annotations | | BioGRID | N/A | Interaction data for *E. coli* proteins | | STRING | P00646 | Predicted protein-protein interaction network | | EcoCyc | EG11203 | *E. coli* pathway and genome database | | ColiBase | ColE1 | Plasmid-specific database | --- ## Related Clinical & Scientific Guides * [tpdA Gene: Structure, Function, and Clinical Significance](/knowledge/bioinformatics/genes/microbiology-amr/tpda-gene-structure-function-pathway) * [acm Gene: Structure, Function, and Clinical Significance](/knowledge/bioinformatics/genes/microbiology-amr/acm-gene-structure-function-pathway) * [P83002 Gene: Structure, Function, and Clinical Significance](/knowledge/bioinformatics/genes/microbiology-amr/p83002-gene-structure-function-pathway) ## References [1] Raibaud O, Mock M, Schwartz M. 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