Laboratory of Biological DNA Modification

Laboratory of Biological DNA Modification (Head scientist – Prof. S. Klimašauskas) studies aspects of mechanistic and structural DNA methylation by applying HhI restriction enzyme methyltransferase (M.HhI) extracted from bacterium Haemophilus haemolyticus that is used as model system.

Nucleobase methylation caused by enzymes helps to receive additional information about composition of organism genomes. DNA methylation is carried out by enzymes-methyltransferases, whereas methylation performs the functions of transcription control, genome imprinting and regulation of eukaryote development. Deviations of these processes influence genetic heredity of human diseases, therefore methyltranferases are the target of anticancer therapy. Methyltransferases constitute an integral part of enzymes in the system of restriction-modification. They exist in most bacterial organisms. Apart from a diverse biological importance, DNA methyltransferases are useful when studying structure of DNA-protein interactions. Bacteria derived enzymes recognize enormous variety (over 200) of short DNA sequences. When analyzing HhI restriction enzymes, it was determined that methytransferase of this restriction enzyme access the target base within double-helix by rotating the nucleotide out of DNA helix into a concave catalytic pocket in the enzyme. Many of DNA correcting and modificating enzymes are characterized by this mechanism.

The main projects conducted in this laboratory analyze kinetic and molecular DNA methylation mechanisms, structures and functions of mammal DNA methylatransferases and conduct the structural works of methyltransferases that perform the particular DNA covalent modification.

This laboratory can provide customers with information about plant DNA changes via methylation. Furthermore, scientific workers of the laboratory can examine the presented samples by using their own equipment: liquid chromatograph and high pressure mass spectrophotometer.