Genome-wide proximity between RNA polymerase and DNA topoisomerase I supports transcription in Streptococcus pneumoniae

PLoS Genet. 2021 Apr 30;17(4):e1009542. doi: 10.1371/journal.pgen.1009542. eCollection 2021 Apr.

Abstract

Streptococcus pneumoniae is a major cause of disease and death that develops resistance to multiple antibiotics. DNA topoisomerase I (TopoI) is a novel pneumococcal drug target. TopoI is the sole type-I pneumococcal topoisomerase that regulates supercoiling homeostasis in this bacterium. In this study, a direct in vitro interaction between TopoI and RNA polymerase (RNAP) was detected by surface plasmon resonance. To understand the interplay between transcription and supercoiling regulation in vivo, genome-wide association of RNAP and TopoI was studied by ChIP-Seq. RNAP and TopoI were enriched at the promoters of 435 and 356 genes, respectively. Higher levels of expression were consistently measured in those genes whose promoters recruit both RNAP and TopoI, in contrast with those enriched in only one of them. Both enzymes occupied a narrow region close to the ATG codon. In addition, RNAP displayed a regular distribution throughout the coding regions. Likewise, the summits of peaks called with MACS tool, mapped around the ATG codon in both cases. However, RNAP showed a broader distribution towards ATG-downstream positions. Remarkably, inhibition of RNAP with rifampicin prevented the localization of TopoI at promoters and, vice versa, inhibition of TopoI with seconeolitsine prevented the binding of RNAP to promoters. This indicates a functional interplay between RNAP and TopoI. To determine the molecular factors responsible for RNAP and TopoI co-recruitment, we looked for DNA sequence motifs. We identified a motif corresponding to a -10-extended promoter for TopoI and for RNAP. Furthermore, RNAP was preferentially recruited to genes co-directionally oriented with replication, while TopoI was more abundant in head-on genes. TopoI was located in the intergenic regions of divergent genes pairs, near the promoter of the head-on gene of the pair. These results suggest a role for TopoI in the formation/stability of the RNAP-DNA complex at the promoter and during transcript elongation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Topoisomerases, Type I / genetics*
  • DNA-Directed RNA Polymerases / genetics*
  • Drug Resistance, Bacterial / genetics
  • Gene Expression Regulation, Bacterial / drug effects
  • Genome, Bacterial / genetics
  • Nucleotide Motifs / drug effects
  • Pneumococcal Infections / drug therapy
  • Pneumococcal Infections / genetics*
  • Pneumococcal Infections / microbiology
  • Promoter Regions, Genetic / genetics
  • Rifampin / pharmacology
  • Streptococcus pneumoniae / genetics*
  • Streptococcus pneumoniae / pathogenicity
  • Surface Plasmon Resonance
  • Transcription, Genetic / drug effects*

Substances

  • DNA-Directed RNA Polymerases
  • DNA Topoisomerases, Type I
  • Rifampin

Grants and funding

This work was supported by the Ministerio de Economía y Competitividad [BIO2017-82951-R to AGC]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.