Solution structure and biophysical properties of MqsA, a Zn-containing antitoxin from Escherichia coli.

摘要: The gene ygiT (mqsA) of Escherichia coli encodes MqsA, the antitoxin motility quorum sensing regulator (MqsR). Both proteins are considered to form a DNA binding complex and be involved in formation biofilms persisters. We have determined three-dimensional solution structure MqsA by high-resolution NMR. protein comprises well-defined N-terminal domain with Zn finger motif usually found eukaryotes, defined C-terminal typical prokaryotic helix-turn-helix motif. two domains almost identical published crystal structures dimeric bound either MqsR or DNA. However, connection flexible linker yields large variety possible conformations solution, which is not reflected structures. binds all four cysteines, stoichiometry 1:1 femtomolar affinity (K(a)≥ 10¹⁷M⁻¹ at 23°C, pH 7.0).