[NMR paper] NMR Characterization of the Interaction of the Endonuclease Domain of MutL with Divalent Metal Ions and ATP.

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NMR Characterization of the Interaction of the Endonuclease Domain of MutL with Divalent Metal Ions and ATP.

Related Articles NMR Characterization of the Interaction of the Endonuclease Domain of MutL with Divalent Metal Ions and ATP.

PLoS One. 2014;9(6):e98554

Authors: Mizushima R, Kim JY, Suetake I, Tanaka H, Takai T, Kamiya N, Takano Y, Mishima Y, Tajima S, Goto Y, Fukui K, Lee YH

Abstract
MutL is a multi-domain protein comprising an N-terminal ATPase domain (NTD) and C-terminal dimerization domain (CTD), connected with flexible linker regions, that plays a key role in DNA mismatch repair. To expand understanding of the regulation mechanism underlying MutL endonuclease activity, our NMR-based study investigated interactions between the CTD of MutL, derived from the hyperthermophilic bacterium Aquifex aeolicus (aqMutL-CTD), and putative binding molecules. Chemical shift perturbation analysis with the model structure of aqMutL-CTD and circular dichroism results revealed that tight Zn2+ binding increased thermal stability without changing secondary structures to function at high temperatures. Peak intensity analysis exploiting the paramagnetic relaxation enhancement effect indicated the binding site for Mn2+, which shared binding sites for Zn2+. The coexistence of these two metal ions appears to be important for the function of MutL. Chemical shift perturbation analysis revealed a novel ATP binding site in aqMutL-CTD. A docking simulation incorporating the chemical shift perturbation data provided a putative scheme for the intermolecular interactions between aqMutL-CTD and ATP. We proposed a simple and understandable mechanical model for the regulation of MutL endonuclease activity in MMR based on the relative concentrations of ATP and CTD through ATP binding-regulated interdomain interactions between CTD and NTD.


PMID: 24901533 [PubMed - as supplied by publisher]



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