Séminaire CIRI: Nicolas MIROUZE
Date / Heure
Date(s) - 04/10/2017
11 h 00 min - 12 h 00 min
Nicolas MIROUZE (Institut de Biologie intégrative de la Cellule (I2BC), Dépt de Microbiologie, Paris – FRANCE):
« Natural transformation and cell wall metabolism in Bacillus subtilis »
Nicolas Mirouze has dedicated his carrier to the study of Horizontal Gene Transfer (HGT) in Gram-positive bacteria. HGT in bacteria may occur via three main mechanisms: transduction, conjugation and genetic transformation. The latter mechanism ensures binding, transport across the cell wall / membrane and homologous recombination of high molecular-weight exogenous DNA with the chromosome of the recipient cell. Genetic transformation is the only of the three mechanisms entirely directed from the recipient cell as all required proteins are encoded in the core chromosome. Expression of genes essential for genetic transformation requires that bacterial cells enter a differentiated state called competence that has been studied in a number of different bacteria.
Nicolas has focused his different projects on the study of natural transformation and competence development in the two main model organisms Streptococcus pneumoniae and Bacillus subtilis and is now interested in Staphyloccocus aureus.
The oral presentation proposed here will particularly describe the early extracellular steps of natural transformation in B. subtilis. Despite decades of investigation, very little was known about exogenous DNA binding at the surface of competent cells and transport across the cell wall. Our results allowed us to understand how the cell wall metabolism is regulated in order to perform natural transformation and to propose an original model (different from what has been suggested in S. pneumoniae) explaining these early extracellular steps in B. subtilis.
Contact: Karen MOREAU