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oai:repisalud.isciii.es:20.500.12105/166952024-11-28T12:36:26Zcom_20.500.12105_2052com_20.500.12105_2051col_20.500.12105_19609col_20.500.12105_25179

00925njm 22002777a 4500 dc García-López, Míriam author Hernández, Pablo author Megías, Diego author Ferrandiz-Avellano, Maria-Jose author de la Campa, Adela G author 2023-10-31 Topoisomerase I (TopoI) in Streptococcus pneumoniae, encoded by topA, is a suitable target for drug development. Seconeolitsine (SCN) is a new antibiotic that specifically blocks this enzyme. We obtained the topARA mutant, which encodes an enzyme less active than the wild type (topAWT) and more resistant to SCN inhibition. Likely due to the essentiality of TopoI, we were unable to replace the topAWT allele by the mutant topARA version. We compared the in vivo activity of TopoIRA and TopoIWT using regulated overexpression strains, whose genes were either under the control of a moderately (PZn) or a highly active promoter (PMal). Overproduction of TopoIRA impaired growth, increased SCN resistance and, in the presence of the gyrase inhibitor novobiocin (NOV), caused lower relaxation than TopoIWT. Differential transcriptomes were observed when the topAWT and topARA expression levels were increased about 5-fold. However, higher increases (10-15 times), produced a similar transcriptome, affecting about 52% of the genome, and correlating with a high DNA relaxation level with most responsive genes locating in topological domains. These results confirmed that TopoI is indeed the target of SCN in S. pneumoniae and show the important role of TopoI in global transcription, supporting its suitability as an antibiotic target. Int J Mol Sci. 2023 Oct 31;24(21):15800. 10.3390/ijms242115800 1422-0067 International journal of molecular sciences 37958782 http://hdl.handle.net/20.500.12105/16695 DNA supercoiling DNA topoisomerase I Seconeolitsine Regulation of supercoiling Transcriptional domains Physiologic and Transcriptomic Effects Triggered by Overexpression of Wild Type and Mutant DNA Topoisomerase I in Streptococcus pneumoniae