Funktionella och Strukturella Studier av Ribosomskafter och GTPaser i Proteinsyntes
Tidsperiod: 2015-01-01 till 2018-12-31
Projektledare: Suparna Sanyal
Budget: 3 350 000 SEK
Despite significant progress in understanding of bacterial protein synthesis several questions remained unanswered. In this project we aim to address some of the unanswered questions. The large subunit of the ribosome possesses two extended conformations, called as L12 stalk and L1 stalk, named after their main protein constituent. The L12 stalk is proposed to be involved in factor recruitment and activation of GTPase factors, while the L1 stalk is believed to be important in ratcheting movement of the ribosomal subunits. We will explore the exact function of the L12 and L1 stalk proteins in well standardized fast-kinetic assays for different steps of translation using quench flow and stopped flow. Further, the sub-steps in peptide elongation with EF-G, and termination involving RF3 will also be studied, which will clarify the role of GTP hydrolysis in these two steps. One major aim is to establish a method for quantitative characterization of the antibiotics targeting ribosome and translation factors. Preliminary results are available for fusidic acid, while we aim to extend the study with actinomycins. Another aim is to characterize relatively less-known translation factors (e.g. ObgE, HflX, RF0 etc.) using structural (X-ray crystallography and cryo-EM) and functional assays. Altogether, this cross-disciplinary project will progress our understanding of the mechanism of protein synthesis and will aid in designing new drugs targeting bacterial protein synthesis machinery.