Electrostatic Interactions at the Dimer Interface Stabilize the E. coli β Sliding Clamp.

ABSTRACT: Sliding clamps are ring-shaped oligomeric proteins that encircle DNA and associate with DNA polymerases for processive DNA replication. The dimeric Escherichia coli β-clamp is closed in solution but must adopt an open conformation to be assembled onto DNA by a clamp loader. To determine what factors contribute to the stability of the dimer interfaces in the closed conformation and how clamp dynamics contribute to formation of the open conformation, we identified conditions that destabilized the dimer and measured the effects of these conditions on clamp dynamics. We characterized the role of electrostatic interactions in stabilizing the β-clamp interface. Increasing salt concentration results in decreased dimer stability and faster subunit dissociation kinetics. The equilibrium dissociatio

SUBMITTER: Purohit A 

PROVIDER: S-EPMC5567426 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature