Download MendeleyElucidation of multiple high-resolution states of human MutS beta by cryo-EM reveals interplay between ATP/ADP binding and heteroduplex DNA recognition.
Lee, J.H., Thomsen, M., Daub, H., Thieulin-Pardo, G., Steinbacher, S., Sztyler, A., Dahiya, V., Neudegger, T., Dominguez, C., Iyer, R.R., Wilkinson, H.A., Monteagudo, E., Plotnikov, N.V., Felsenfeld, D.P., Haque, T.S., Finley, M., Boudet, J., Vogt, T.F., Prasad, B.C.(2025) Nucleic Acids Res 53
- PubMed: 40613711 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1093/nar/gkaf604
- Primary Citation Related Structures:
8OLX, 8OM5, 8OM9, 8OMA, 8OMO, 8OMQ, 8RZ7, 8RZ8, 8RZ9 - PubMed Abstract:
Human and mouse genetic studies have demonstrated a role for DNA mismatch repair (MMR) molecular machines in modulating the rate of somatic expansion of the huntingtin (HTT) CAG repeats, and onset and progression of Huntington's Disease (HD). MutSβ, a key component of the MMR pathway, is a heterodimeric protein of MSH2 and MSH3 that recognizes and initiates the repair of extrahelical DNA extrusions. Loss-of-function of mouse Msh3 and reduced-expression alleles of human MSH3 lead to slower rates of somatic expansion and delayed disease onset in humans, signifying MSH3 as a promising therapeutic target for HD. Here we report biochemical and cryo-electron microscopy analyses of human MutSβ, demonstrating MutSβ undergoes conformational changes induced by nucleotide and DNA binding. We present multiple conformations of MutSβ including the DNA-free MutSβ compatible with precisely complementary base-paired homoduplex DNA binding, two distinct structures of MutSβ bound to (CAG)2 DNA, a sliding clamp form and a DNA-unbound, ATP-bound conformation. Along with evidence for novel conformational states adopted by MutSβ to initiate the MMR cascade, these structures provide a foundation for structure-guided drug discovery.
- Proteros biostructures GmbH, Bunsenstr 7a, Martinsried, 82152, Germany.
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