Potassium Glutamate and Glycine Betaine Induce Self-Assembly of the PCNA and β-Sliding Clamps.

ABSTRACT: Sliding clamps are oligomeric ring-shaped proteins that increase the efficiency of DNA replication. The stability of the Escherichia coli β-clamp, a homodimer, is particularly remarkable. The dissociation equilibrium constant of the β-clamp is of the order of 10 pM in buffers of moderate ionic strength. Coulombic electrostatic interactions have been shown to contribute to this remarkable stability. Increasing NaCl concentration in the assay buffer results in decreased dimer stability and faster subunit dissociation kinetics in a way consistent with simple charge-screening models. Here, we examine non-Coulombic ionic effects on the oligomerization properties of sliding clamps. We determined relative diffusion coefficients of two sliding clamps using fluorescence correlation spectroscopy. Re

SUBMITTER: Purohit A 

PROVIDER: S-EPMC7820735 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature