Structural characterization of a membrane protein complex involved in bacterial cell wall synthesis

• Grant number: 15/20278-9
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: February 10, 2016
• End date: February 09, 2017
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Andrea Dessen de Souza e Silva
• Grantee: Lucas Mayrink Assis
• Supervisor: Andrea Dessen de Souza e Silva
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil
• Institution abroad: Institut de Biologie Structurale (IBS), France
• Associated to the scholarship: 13/22681-0 - Structural characterization of membrane protein complexes involved in bacterial cell wall biosynthesis, BP.DD

Abstract

The cell wall is an essential structure for bacterial survival, being responsible for several vital cellular functions such as division, elongation, secretion of virulence factors, and adhesion. Its main constituent is the peptidoglycan, a polymer formed by polymerized glycan chains cross-linked by stem peptides. The enzymes which participate in peptidoglycan synthesis act in an orchestrated manner forming large macromolecular complexes, one of which consists of the interaction between the "flippases" and the Penicillin Binding Proteins (PBP-s). Some species of bacteria, for instance, Clostridium difficile, express these two proteins as chimeras, in which a single polypeptide expresses both "flippase" and "PBP" activities. The main objective of this project is to crystallize and solve the structure of the first "Flippase-PBP", which will provide key insight not only into the peptidoglycan biosynthesis field but will also open avenues towards the development of novel potential antibiotics. Crystallization of membrane proteins is a challenging endeavor, and requires the mastering of techniques including lipidic cubic phase, bicelles, vapor diffusion, free-interface diffusion, and microbatch experiments. In order to learn these methodologies, the student, Lucas Mayrink Assis, presently doing his PhD in the Dessen lab at the LNBio in Campinas, is applying for a BEPE fellowship to spend one year in the other part of the Dessen lab at the "Institut de Biologie Structurale" (IBS), in Grenoble, France. At the IBS, the student will have the support of Andréa Dessen's research team, which has a great deal of experience in the purification and crystallization of membrane proteins, as well as have access to state-of-the-art facilities in the Grenoble area, such as the ESRF synchrotron and lipidic cubic crystallization technology. (AU)