Characterizing the ATP-Induced Structural Changes of the N-terminal Domain of Pms1 by Oxidative Surface Mapping and Mass Spectrometry

摘要

Mismatch repair (MMR) corrects base insertions, deletions and misincorporations that occur during DNA replication. Matl(alpha), comprised of Mlh1 and Pms1 in yeast, undergoes significant conformational changes that cycle with the binding, hydrolysis and release of ATP~(2). These changes in structure are though to play a role in coordinating strand recognition with nucleotide excision and repair. In addition to binding ATP, the highly-conserved N-terminal domains of MultL (E.coli), Pms2 (human) and Pms1 bind DNA during MMR. Differential oxidative surface mapping coupled with mass spectrometry has been used to identify residues of the N-terminal domain of Pms1 (Pms1-NTD) that are protected upon binding of ATP and/or DNA. Limited proteolysis followed by mass spectrometric analysis has also been used to probe the DNA binding site of PMS1-NTD.