ANTIBIOTICS GROUP of Molecular Microbiology Laboratory

We study the mechanisms of action of antibiotics. One of our major research topics are the studies on inhibitors of protein synthesis. In this field we have been mostly focused on macrolides. Macrolides (of which erythromycin is the most well known example) bind to the large ribosomal subunit and inhibit exit of the newly made nascent peptide chain from the ribosome. We have characterized the length of the nascent peptide chain at which translation starts to be inhibited. In addition, we have observed that the extent of inhibition depends on the sequence of the nascent peptide chain, some nascent peptides being able to remove the drug from the ribosome and thus causing antibiotic resistance.

Another line of research is looking at the differentiation of bacterial cultures into cells with different properties. This phenomenon is observed when the bacterial cultures enter into stationary growth phase. It is important to note that these different bacterial cells have different sensitivity to antibiotics, some of them being able to “persist” at high concentrations of the drugs. Our aim is to characterize these different bacterial cells and to elucidate the molecular mechanisms responsible for this differentiation.

We are also looking at the evolution of the translational apparatus. We analyzed the sequence context for initiation of translation in different organisms. We have also annotated and analyzed the genes for ribosome associated GTPases in most of the fully sequenced bacterial genomes. These projects are done in collaboration with Prof Maido Remm from the Institute of Molecular and Cell Biology (UT).

We several other longstanding collaborations:

• Prof Måns Ehrenberg (Uppsala University, Sweden),
• Prof Alexander Mankin (University of Illinois at Chicago),
• Prof Jaanus Remme (Institute of Molecular and Cell Biology)
• Prof Andres Merits (Institute of Technology).

Contact: , Professor in the technology of antimicrobial compounds, Tel:  +372 737 4844
Nooruse St 1 room 425, Tartu ESTONIA