Journal Article

Large conformational changes in MutS during DNA scanning, mismatch recognition and repair signalling

Hingorani, Manju M, Harris, Credle, Sharma, Anushi, Qiu, Ruoyi, DeRocco, Vanessa C, Weninger, Keith R, Erie, Dorothy A

2012

Overview

MutS protein recognizes mispaired bases in DNA and targets them for mismatch repair. Little is known about the transient conformations of MutS as it signals initiation of repair. We have used single‐molecule fluorescence resonance energy transfer (FRET) measurements to report the conformational dynamics of MutS during this process. We find that the DNA‐binding domains of MutS dynamically interconvert among multiple conformations when the protein is free and while it scans homoduplex DNA. Mismatch recognition restricts MutS conformation to a single state. Steady‐state measurements in the presence of nucleotides suggest that both ATP and ADP must be bound to MutS during its conversion to a sliding clamp form that signals repair. The transition from mismatch recognition to the sliding clamp occurs via two sequential conformational changes. These intermediate conformations of the MutS:DNA complex persist for seconds, providing ample opportunity for interaction with downstream proteins required for repair. New intermediates in the nucleotide‐dependent transition from mismatch recognition to repair‐initiating sliding clamp are revealed via single‐molecule FRET of the key mismatch repair protein MutS.

• Publisher: John Wiley & Sons, Ltd,Nature Publishing Group UK,Springer Nature B.V,Nature Publishing Group
• Subject: Adenosine diphosphate / Adenosine Diphosphate - chemistry / Adenosine Triphosphate - chemistry / ATP / Biophysics / Deoxyribonucleic acid / DNA / DNA damage / DNA mismatch repair / DNA Mismatch Repair - genetics / DNA Mismatch Repair - physiology / DNA repair / EMBO13 / Energy transfer / Fluorescence / Fluorescence Resonance Energy Transfer / MMR / Molecular biology / MutS / MutS DNA Mismatch-Binding Protein - chemistry / MutS DNA Mismatch-Binding Protein - genetics / MutS DNA Mismatch-Binding Protein - metabolism / Protein Conformation / protein conformational change / Proteins / Resonance / Signal transduction / sliding clamp