Le Professeur Mélanie Etheve-Quelquejeu donnera un séminaire intitulé:
"Chimie des nucléosides et nucléotides pour l'étude mécanistique et structurale d'une cible biologique impliquée dans la biosynthèse du peptidoglycane"

le jeudi 11 Décembre 2014 à 11h00 (Auditorium D. Chemla - Bâtiment IDA)



Résumé:
The tRNA-dependent aminoacyl Fem transferases catalyze an essential step of peptidoglycan synthesis in pathogenic bacteria and are considered as attractive target for the development of novel antibiotics. FemX of Weissella Viridescens FemXwv, the model enzyme of this family, transfers L-Ala from Ala-tRNA to the -amino group of L-Lys in the peptidoglycan precursor UDP-MurNAcpentapeptide (UM5K). To gain insight into the catalytic mechanism of non-ribosomal amino acid transferases, we synthesized peptidyl-RNA conjugates for co-crystallization with FemXWv of Weissella viridescens. The structure of the resulting complex and mutational studies revealed the mechanism by which FemXWv binds its substrates for substrate-assisted catalysis and stabilization of the tetrahedral intermediate.