Doctoral defence: Kaspar Reier „Quantity, stability and disparity of ribosomal components in Escherichia coli stationary phase“

On November 20 at 2:15 Kaspar Reier will defend his Doctoral Thesis on Molecular Biology „Quantity, stability and disparity of ribosomal components in Escherichia coli stationary phase“.  

Supervisors

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Associate Professor Aivar Liiv, (UT)

Associate Professor Jaanus Remme, (UT)

Opponent

Professor Suparna Chandra Sanyal, Head of Molecular Biology Division, Uppsala University, Sweden

Summary

Ribosomes are macromolecular complexes present in every living organism. The function of ribosomes in nature is protein synthesis. Proteins are polymers composing of amino acids, with multiple functions in biology. Some proteins have catalytic activity while others fulfill structural or mechanical roles in nature. Interestingly ribosomes themselves compose of proteins, hence the product of their main function- protein synthesis, is also necessary for their efficient functioning. R-protein research is integral to understand molecular mechanism like antibiotic resistance, protein synthesis regulation, and ribosome assembly or degradation. In this work, we studied ribosome stabilities and translation activity in stationary phase with a focus on r-proteins. In this work we show how ribosome protein composition changes when Escherichia coli cells transition into stationary phase. Interestingly, ribosome protein composition continues to change even in prolonged stationary phase. In correlation with ribosome r-protein composition, we also see increases and decreases in translation activity. Furthermore, individual r-protein stabilities in proteome were determined during stationary phase. Based on their stability r-proteins are divided into two groups: 30 stable r-proteins and 21 short-lived r-proteins. This work complements our knowledge about ribosomes and translation under growth restricting conditions.