The E. coli γ clamp loader is a pentameric complex of δ, δ' and three γ subunits that opens and loads β-clamp proteins onto DNA in an ATP-dependent process essential for efficient DNA replication. ATP binding to the γ subunits promotes conformational changes that enable the clamp loader to bind and open the ring-shaped β-clamp homodimer. Here we report the nearly complete backbone and side-chain 1H, 13C and 15N NMR resonance assignments of the 242-residue truncated γ subunit of the clamp loader complex, which includes the N-terminal mini (domain I) and lid (domain II) domains. This construct represents the nucleotide binding module in the clamp loader complex and provides a model system for studies of conformational rearrangements of the clamp loader induced by nucleotide binding.
Keywords: ATP binding; Bacterial DNA replication; Pol III holoenzyme; Processivity β clamp; Protein–protein interactions; γ clamp loader complex.
© 2021. The Author(s), under exclusive licence to Springer Nature B.V.