Role of Arg243 and His239 Residues in the Recognition of Damaged Nucleotides by Human Uracil-DNA Glycosylase SMUG1

In this study, we investigated the kinetics of conformational transitions in the protein and in various DNA substrates during enzymatic catalysis using the stopped-flow method based on changes in the fluorescence intensity of enzyme ’s tryptophan residues and 2-aminopurine in DNA or fluorescence resonance energy transfer (FRET) between fluorophores in DNA. The kinetic mechanism of interactions between reaction intermediates was identified, and kinetic parameters of the intermediate formation and dissociation were calculated. The obtained data help in elucidating the functions of His239 and Arg243 residues in the recognition and removal of damaged nucleotides by SMUG1.

Source: Biochemistry (Moscow) - April 30, 2020 Category: Biochemistry Source Type: research