title: NMR characterization of the interaction of the endonuclease domain of MutL with divalent metal ions and ATP.
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 Zn(2+) 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 Mn(2+), which shared binding sites for Zn(2+). 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.
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Mizushima
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Ju Yaen
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Suetake
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Takai
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Narutoshi
authors.initials: N
authors.lastname: Kamiya
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Takano
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Mishima
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
authors.affiliation: RIKEN SPring-8 Center, Harima Institute, Sayo-cho, Sayo-gun, Hyogo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukui
authors.affiliation: Institute for Protein Research, Osaka University, Suita, Osaka, Japan.
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Lee
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D004720:Endonucleases / Q000737:chemistry* / Q000378:metabolism; D007477:Ions / Q000737:chemistry* / Q000378:metabolism; D008670:Metals / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D012996:Solutions; D013816:Thermodynamics
chemical_list: D001426:Bacterial Proteins; D007477:Ions; D008670:Metals; D012996:Solutions; D000255:Adenosine Triphosphate; D004720:Endonucleases; D000251:Adenosine Triphosphatases