Emily Helgesen

  • Researcher; PhD

Emily Helgesen’s project group:
Bacterial DNA repair and nucleoid dynamics

Maintaining DNA integrity is critical for the survival of all species. Bacteria like Escherichia coli respond to DNA damage by activating the so-called SOS response, which leads to the expression of around 50 genes encoding proteins of unknown function, repair proteins and error-prone polymerases. This process often results in mutations and antibiotic resistance and activates the transfer of resistance genes between bacteria. Understanding the underlying mechanisms is crucial for developing preventive measures against antibiotic resistance and novel treatments for antibiotic resistant infections.

Our project group investigates how bacteria respond to DNA-damaging antibiotics, with a focus on DNA dynamics, DNA compaction and DNA repair mechanisms. We examine the roles of various nucleoid binding proteins, including the bacterial sliding clamp, SMC-like proteins, and repair proteins in these processes. Additionally, we are engaged in innovation projects to develop novel peptide-based antibiotics. Our efforts also include working with infection clinicians at OUH to evaluate the efficacy of combinatorial antibiotic treatments for extensively resistant bacterial strains.

Projects:

  • DNA dynamics and mechanisms of DNA compaction following antibiotic exposure.
  • The bacterial sliding clamp: novel interaction partners and importance under stress
  • Development of peptide-based antibiotics
  • Antibiotic combinatorial treatment
Time-lapse imaging of an E. coli cell treated with a DNA-damaging antibiotic, illustrating significant compaction of the DNA (pink) and the dynamic behavior of an associated repair protein (green).
 

Publications 2025

Sæbø IP, Dyhr E, Riisnæs IMM, Franzyk H, Bjørås M, Booth JA, Helgesen E (2025)
Rational design of synthetic antimicrobial peptides based on the Escherichia coli ShoB toxin
Sci Rep, 15 (1), 14354
DOI 10.1038/s41598-025-98330-3, PubMed 40274891

Publications 2023

Sæbø IP, Bjørås M, Franzyk H, Helgesen E, Booth JA (2023)
Optimization of the Hemolysis Assay for the Assessment of Cytotoxicity
Int J Mol Sci, 24 (3)
DOI 10.3390/ijms24032914, PubMed 36769243

Publications 2021

Helgesen E, Sætre F, Skarstad K (2021)
Topoisomerase IV tracks behind the replication fork and the SeqA complex during DNA replication in Escherichia coli
Sci Rep, 11 (1), 474
DOI 10.1038/s41598-020-80043-4, PubMed 33436807

Publications 2020

Nedal A, Ræder SB, Dalhus B, Helgesen E, Forstrøm RJ, Lindland K, Sumabe BK, Martinsen JH, Kragelund BB, Skarstad K, Bjørås M, Otterlei M (2020)
Peptides containing the PCNA interacting motif APIM bind to the β-clamp and inhibit bacterial growth and mutagenesis
Nucleic Acids Res, 48 (10), 5540-5554
DOI 10.1093/nar/gkaa278, PubMed 32347931

Publications 2017

Flåtten I, Helgesen E, Pedersen IB, Waldminghaus T, Rothe C, Taipale R, Johnsen L, Skarstad K (2017)
Phenotypes of dnaXE145A Mutant Cells Indicate that the Escherichia coli Clamp Loader Has a Role in the Restart of Stalled Replication Forks
J Bacteriol, 199 (24)
DOI 10.1128/JB.00412-17, PubMed 28947673

Pedersen IB, Helgesen E, Flåtten I, Fossum-Raunehaug S, Skarstad K (2017)
SeqA structures behind Escherichia coli replication forks affect replication elongation and restart mechanisms
Nucleic Acids Res, 45 (11), 6471-6485
DOI 10.1093/nar/gkx263, PubMed 28407100

Publications 2016

Helgesen E, Fossum-Raunehaug S, Skarstad K (2016)
Lack of the H-NS Protein Results in Extended and Aberrantly Positioned DNA during Chromosome Replication and Segregation in Escherichia coli
J Bacteriol, 198 (8), 1305-16
DOI 10.1128/JB.00919-15, PubMed 26858102

Publications 2015

Helgesen E, Fossum-Raunehaug S, Sætre F, Schink KO, Skarstad K (2015)
Dynamic Escherichia coli SeqA complexes organize the newly replicated DNA at a considerable distance from the replisome
Nucleic Acids Res, 43 (5), 2730-43
DOI 10.1093/nar/gkv146, PubMed 25722374

Publications 2014

Fossum-Raunehaug S, Helgesen E, Stokke C, Skarstad K (2014)
Escherichia coli SeqA structures relocalize abruptly upon termination of origin sequestration during multifork DNA replication
PLoS One, 9 (10), e110575
DOI 10.1371/journal.pone.0110575, PubMed 25333813

Publications 2012

Hak S, Helgesen E, Hektoen HH, Huuse EM, Jarzyna PA, Mulder WJ, Haraldseth O, Davies Cde L (2012)
The effect of nanoparticle polyethylene glycol surface density on ligand-directed tumor targeting studied in vivo by dual modality imaging
ACS Nano, 6 (6), 5648-58
DOI 10.1021/nn301630n, PubMed 22671719

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