Gruic group photo

Our group forms the Division of Biochemistry within the Department of Chemistry, Faculty of Science, University of Zagreb in Zagreb, Croatia. Our research is focused on aminoacyl-tRNA synthetases (aaRSs), a group of ancient enzymes crucial for protein biosynthesis. Each aaRS is responsible for covalent coupling (aminoacylation) of cognate tRNA with its cognate amino acid. The aminoacylated tRNA then transports the amino acid to the ribosome for incorporation into the growing polypeptide chain. Choosing the correct amino acid in the cellular pool is a formidable task for some aaRSs, as they are unable to discriminate against similar proteinogenic and non-proteinogenic amino acids at the level of aminoacylation with the accuracy above the experimentaly determined threshold levels of translational fidelity (1 in 10 000). These aaRSs have developed a diverse set of proofreading (editing) reactions to hydrolyze incorrectly formed intermediates and/or products. In recent years, we have been particularly focused on quality control mechanisms that preserve accurate translation of isoleucine, leucine and valine codons in Escherichia coli. We also research homologs of aminoacyl-tRNA synthetases and try to elucidate their celullar roles, plant aminoacyl-tRNA synthetases and search for proteins that form complexes with aminoacyl-tRNA synthetases and thereby influence their activity.