CRC 858 B13 - Molecular Basis for the Cooperative Action of the Reverse Gyrase Helicase and Topoisomerase Domains in Positive DNA Supercoiling

Basic data for this project

Description

Reverse gyrase is a DNA topoisomerase that consists of a helicase and a topoisomerase domain. The intricate cooperation of these domains generates the novel function of ATP-dependent positive DNA supercoiling. In the tRNA acetylase TmcA, a helicase and a transacetylase domain cooperate in tRNA acetylation. We will analyze the cooperativity involved in DNA binding to reverse gyrase by cross-linking/mass-spectrometry and X-ray crystallography, and dissect the temporal coordination of cooperative conformational changes throughout the nucleotide cycle of reverse gyrase by single-molecule FRET. Further, we will address cooperativity in ligand binding by and conformational changes of TmcA during tRNA acetylation. The goal is to unravel the molecular basis for the functional interplay between helicase domains and other enzymatic domains.