Native mass spectrometry provides direct evidence for DNA mismatch-induced regulation of asymmetric nucleotide binding in mismatch repair protein MutS.

ABSTRACT: The DNA mismatch repair protein MutS recognizes mispaired bases in DNA and initiates repair in an ATP-dependent manner. Understanding of the allosteric coupling between DNA mismatch recognition and two asymmetric nucleotide binding sites at opposing sides of the MutS dimer requires identification of the relevant MutS.mmDNA.nucleotide species. Here, we use native mass spectrometry to detect simultaneous DNA mismatch binding and asymmetric nucleotide binding to Escherichia coli MutS. To resolve the small differences between macromolecular species bound to different nucleotides, we developed a likelihood based algorithm capable to deconvolute the observed spectra into individual peaks. The obtained mass resolution resolves simultaneous binding of ADP and AMP.PNP to this ABC ATPase in the abse

SUBMITTER: Monti MC 

PROVIDER: S-EPMC3185415 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature