The acidic C-terminal tail of DNA Gyrase of Salmonella enterica serovar Typhi controls DNA relaxation in an acidic environment.

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  • Additional Information
    • Source:
      Publisher: Elsevier Country of Publication: Netherlands NLM ID: 7909578 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-0003 (Electronic) Linking ISSN: 01418130 NLM ISO Abbreviation: Int J Biol Macromol Subsets: MEDLINE
    • Publication Information:
      Publication: Amsterdam : Elsevier
      Original Publication: Guildford, Eng., IPC Science and Technology Press.
    • Subject Terms:
      DNA Gyrase*/genetics ; Salmonella typhi*/genetics; Escherichia coli/genetics ; DNA ; DNA, Superhelical/genetics ; DNA Topoisomerases, Type I/metabolism ; DNA Topoisomerases, Type II/metabolism
    • Abstract:
      The intracellular bacteria, Salmonella Typhi adapts to acidic conditions in the host cell by resetting the chromosomal DNA topology majorly controlled by DNA Gyrase, a Type II topoisomerase. DNA Gyrase forms a heterodimer A 2 B 2 complex, which manages the DNA supercoiling and relaxation in the cell. DNA relaxation forms a part of the regulatory mechanism to activate the transcription of genes required to survive under hostile conditions. Acid-induced stress attenuates the supercoiling activity of the DNA Gyrase, resulting in DNA relaxation. Salmonella DNA becomes relaxed as the bacteria adapt to the acidified intracellular environment. Despite comprehensive studies on DNA Gyrase, the mechanism to control supercoiling activity needs to be better understood. A loss in supercoiling activity in E. coli was observed upon deletion of the non-conserved acidic C-tail of Gyrase A subunit. Salmonella Gyrase also contains an acidic tail at the C-terminus of Gyrase A, where its deletion resulted in reduced supercoiling activity compared to wild-type Gyrase. Interestingly, we also found that wild-type Gyrase compromises supercoiling activity at acidic pH 2-3, thereby causing DNA relaxation. The absence of a C-tail displayed DNA supercoiling to some extent between pH 2-9. Hence, the C-tail of Gyrase A might be one of the controlling factors that cause DNA relaxation in Salmonella at acidic pH conditions. We propose that the presence of the C-tail of GyraseA causes acid-mediated inhibition of the negative supercoiling activity of Gyrase, resulting in relaxed DNA that attracts DNA-binding proteins for controlling the transcriptional response.
      Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
      (Copyright © 2024 Elsevier B.V. All rights reserved.)
    • Contributed Indexing:
      Keywords: ATPase assay; Acidic tail; DNA relaxation; DNA supercoiling; EMSA; Gyrase; Salmonella Typhi; Topoisomerase
    • Accession Number:
      EC 5.99.1.3 (DNA Gyrase)
      9007-49-2 (DNA)
      0 (DNA, Superhelical)
      EC 5.99.1.2 (DNA Topoisomerases, Type I)
      EC 5.99.1.3 (DNA Topoisomerases, Type II)
    • Publication Date:
      Date Created: 20240125 Date Completed: 20240311 Latest Revision: 20240311
    • Publication Date:
      20240311
    • Accession Number:
      10.1016/j.ijbiomac.2024.129728
    • Accession Number:
      38272423