HDX/MS of the E. coli replicative DNA polymerase identifies stabilizing interactions between the DNA sliding clamp, exonuclease and clamp loader

摘要

HDX analysis of the complex -τ and-DNA indicated the complex is not stable. There were a large number of peptides showing EX1 and EX2 kinetics, indicating that the subunits were moving rapidly between conformations. When τ and DNA are present in the complex, the structure is stabilized. This directed the most appropriate subunit selection for the cryoEM studies (4). The conformational change in the polymerase tail/τ_(500) region seen by cryoelectrom microscopy (4) is also identified by HDX.