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    topA DNA topoisomerase 1 [ Escherichia coli str. K-12 substr. MG1655 ]

    Gene ID: 945862, updated on 3-Dec-2024

    Summary

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    Official Symbol
    topA
    Official Full Name
    DNA topoisomerase 1
    Primary source
    ECOCYC:EG11013
    Locus tag
    b1274
    See related
    ASAP:ABE-0004275
    Gene type
    protein coding
    RefSeq status
    PROVISIONAL
    Organism
    Escherichia coli str. K-12 substr. MG1655 (strain: K-12, substrain: MG1655)
    Lineage
    Bacteria; Pseudomonadota; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia
    Also known as
    ECK1268; supX
    Summary
    Topoisomerase I is a type IA topoisomerase which is responsible for relaxing negative supercoils in DNA. [More information is available at EcoCyc: EG11013].
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    Genomic context

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    Sequence:
    NC_000913.3 (1331048..1333645)

    NC_000913.3Genomic Context describing neighboring genes Neighboring gene S49 peptidase family protein Neighboring gene protein YciN Neighboring gene DNA-binding transcriptional dual regulator CysB Neighboring gene uncharacterized protein YmiA

    Genomic regions, transcripts, and products

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    Genomic Sequence:
    NC_000913.3

    Go to nucleotide: Graphics FASTA GenBank

    Bibliography

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    Related articles in PubMed

    1. Protein-nucleotide interactions in E. coli DNA topoisomerase I. Feinberg H, et al. Nat Struct Biol, 1999 Oct. PMID 10504732
    2. Crystallization of a 67 kDa fragment of Escherichia coli DNA topoisomerase I. Lima CD, et al. J Mol Biol, 1993 Aug 20. PMID 8396651
    3. Effect of the deletion of the sigma 32-dependent promoter (P1) of the Escherichia coli topoisomerase I gene on thermotolerance. Qi H, et al. Mol Microbiol, 1996 Aug. PMID 8878034
    4. Regulation of Escherichia coli topA gene transcription: involvement of a sigmaS-dependent promoter. Qi H, et al. J Mol Biol, 1997 Apr 4. PMID 9126832
    5. DNA supercoiling and bacterial adaptation: thermotolerance and thermoresistance. Tse-Dinh YC, et al. Trends Microbiol, 1997 Aug. PMID 9263411

    See all (120) citations in PubMed

    GeneRIFs: Gene References Into Functions

    What's a GeneRIF?
    1. Topoisomerase I Essentiality, DnaA-Independent Chromosomal Replication, and Transcription-Replication Conflict in Escherichia coli.
      Title: Topoisomerase I Essentiality, DnaA-Independent Chromosomal Replication, and Transcription-Replication Conflict in Escherichia coli.
    2. Supercoiling, R-loops, Replication and the Functions of Bacterial Type 1A Topoisomerases.
      Title: Supercoiling, R-loops, Replication and the Functions of Bacterial Type 1A Topoisomerases.
    3. we observe that a single residue substitution (R168C) results in a high rate of head-to-tail (tandem) short sequence duplications, which are independent of existing sequence repeats. Finally, we show that the unique mutation spectrum of topA mutants enhances the emergence of antibiotic resistance in comparison to mismatch-repair (mutS) mutators, and leads to new resistance genotypes.
      Title: Point mutations in topoisomerase I alter the mutation spectrum in E. coli and impact the emergence of drug resistance genotypes.
    4. Study finding that both E. coli topo I and III control R-loop formation/accumulation, mostly to inhibit unregulated replication, may suggest that R-loops have been a problem early in the evolution of life. Furthermore, data show that E. coli cells can survive in the absence of type 1A topos, owing to the surproduction of topo IV that can relax excess negative supercoiling and prevent R-loop formation.
      Title: Topoisomerases I and III inhibit R-loop formation to prevent unregulated replication in the chromosomal Ter region of Escherichia coli.
    5. the CyaA(N600Y) mutant has a transcriptome indicative of increased CRP activity, pointing to an unknown role for CyaA and / or cAMP in gene expression..We show that the large scale transcriptomic changes in the topoisomerase I (FusA(A608E)-TopA(S180L)) mutant likely result from increased negative supercoiling in the cell.
      Title: Modulation of Global Transcriptional Regulatory Networks as a Strategy for Increasing Kanamycin Resistance of the Translational Elongation Factor-G Mutants in Escherichia coli.
    6. Escherichia coli RecA physically interacts with topoisomerase I to modulate the chromosomal DNA supercoiling.
      Title: Investigating direct interaction between Escherichia coli topoisomerase I and RecA.
    7. Structural study shows how the C-terminal domains of E. coli topoisomerase I bind single-stranded DNA to recognize the accumulation of negative supercoils in duplex DNA.
      Title: Structural basis for suppression of hypernegative DNA supercoiling by E. coli topoisomerase I.
    8. Antimicrobial susceptibility and SOS-dependent increase in mutation frequency are impacted by Escherichia coli topoisomerase I C-terminal point mutation.
      Title: Antimicrobial Susceptibility and SOS-Dependent Increase in Mutation Frequency Are Impacted by Escherichia coli Topoisomerase I C-Terminal Point Mutation.
    9. Data indicate that transcription-coupled DNA supercoiling (TCDS) in topoisomerase I deficient (topA) is dependent on promoter strength.
      Title: Dependence of transcription-coupled DNA supercoiling on promoter strength in Escherichia coli topoisomerase I deficient strains.
    10. Topoisomerase I relaxes DNA in slow processive runs but with short pauses before runs.
      Title: Bacterial topoisomerase I and topoisomerase III relax supercoiled DNA via distinct pathways.
    Submit: New GeneRIF Correction See all GeneRIFs (19)

    Interactions

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    Products Interactant Other Gene Complex Source Pubs Description

    General gene information

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    Homology

    Gene Ontology Provided by EcoCyc

    Function Evidence Code Pubs
    enables DNA binding IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables DNA topoisomerase activity IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables DNA topoisomerase activity IMP
    Inferred from Mutant Phenotype
    more info
    		 PubMed 
    enables DNA topoisomerase type I (single strand cut, ATP-independent) activity IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables DNA topoisomerase type I (single strand cut, ATP-independent) activity IMP
    Inferred from Mutant Phenotype
    more info
    		 PubMed 
    enables RNA topoisomerase activity IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    enables metal ion binding IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables protein binding IPI
    Inferred from Physical Interaction
    more info
    		 PubMed 
    Process Evidence Code Pubs
    involved_in DNA topological change IEA
    Inferred from Electronic Annotation
    more info
    		  
    acts_upstream_of_or_within DNA topological change IGI
    Inferred from Genetic Interaction
    more info
    		 PubMed 
    Component Evidence Code Pubs
    located_in chromosome IEA
    Inferred from Electronic Annotation
    more info
    		  
    located_in cytosol IDA
    Inferred from Direct Assay
    more info
    		 PubMed 

    General protein information

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    Preferred Names
    DNA topoisomerase 1
    NP_415790.1

    NCBI Reference Sequences (RefSeq)

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    Genome Annotation

    The following sections contain reference sequences that belong to a specific genome build. Explain

    Reference assembly

    Genomic

    1. NC_000913.3 Reference assembly

      Range
      1331048..1333645
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    mRNA and Protein(s)

    1. NP_415790.1 DNA topoisomerase 1 [Escherichia coli str. K-12 substr. MG1655]

      See identical proteins and their annotated locations for NP_415790.1

      Status: PROVISIONAL

      UniProtKB/TrEMBL
      A0A8S7BEL4
      Conserved Domains (1) summary
      PRK07561
      Location:2 → 849
      PRK07561; DNA topoisomerase I subunit omega; Validated
    Nucleotide Protein
    Heading Accession and Version

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