Directeur de Recherche, CNRS
05 61 33 59 72
Researcher emeritus Researcher
- Nathalie Campo
- Jean-Pierre Claverys
- Maud Hertzog
- Calum Johnston
- Mathieu Berge
- Marc Prudhomme
- Violette Morales
- Isabelle Mortier
The pneumococcal transformation team combines complementary approaches to study all aspects of genetic transformation in the human pathogen Streptococcus pneumoniae (the pneumococcus). Transformation is a mechanism of horizontal gene transfer entirely encoded by the recipient cell. It involves capture of exogenous DNA, internalization in the form of single strands and integration into the recipient chromosome by homologous recombination, driven by the recombinase RecA. This process is widespread in the bacterial kingdom and promotes acquisition of new genetic traits. In the pneumococcus, transformation occurs during a short window called competence and can mediate the spread of antibiotics and vaccine escape. Our team combines molecular genetics, cell biology, biochemistry and single molecule analyses to study the pneumococcal transformation process. The main projects of our team focus on:
- the mechanisms and proteins involved in the transformation process at a molecular level
- how competence is integrated into and controls the pneumococcal cell cycle
- how competence and transformation impact chromosome dynamics
- homologous recombination mediated by RecA and partners using single molecule studies
- the complex regulatory cascade and sensory cues controlling competence induction
Through these complementary projects, we aim to further our fundamental understanding of this widespread, clinically relevant process.
Chomosome dynamics during pneumococcal competence for transtormation
Pneumococcal competence regulation
Transformation machinery (TRAM)
Single molecule analysis of recombination during transformation (SMART)
- Johnston C, Hauser C, Hermans PW, Martin B, Polard P, Bootsma HJ, Claverys JP..
Fine-tuning of choline metabolism is important for pneumococcal colonization.
- Johnston C, Bootsma HJ, Aldridge C, Manuse S, Gisch N, Schwudke D, Hermans PW, Grangeasse C, Polard P, Vollmer W, Claverys JP..
Co-Inactivation of GlnR and CodY Regulators Impacts Pneumococcal Cell Wall Physiology.
- Johnston C, Mortier-Barrière I, Granadel C, Polard P, Martin B, Claverys JP..
RecFOR is not required for pneumococcal transformation but together with XerS for resolution of chromosome dimers frequently formed in the process.
- Johnston C, Martin B, Fichant G, Polard P, Claverys JP..
Bacterial transformation: distribution, shared mechanisms and divergent control.
Nature Reviews Microbiology
- Johnston C, Campo N, Bergé MJ, Polard P, Claverys JP. .
Streptococcus pneumoniae, le transformiste.
Trends in Microbiology
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