Abstract

Clamp loaders are required to load the ring-shaped clamps that tether replicative DNA polymerases onto DNA. Recently solved crystal structures, along with a series of biochemical studies, have provided a detailed understanding of the clamp loading reaction. In particular, studies of the Escherichia coli clamp loader — an AAA+ machine — have provided insights into the architecture of clamp loaders from eukaryotes, bacteriophage T4 and archaea. Other AAA+ proteins are also involved in the initiation of DNA replication, and studies of the E. coli clamp loader indicate mechanisms by which these proteins might function.

Author affiliations

1. Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, New York, 10021, USA.
2. Departments of Molecular and Cell Biology, and Chemistry, Howard Hughes Medical Institute, The University of California, Berkeley, California 94720, USA.
3. Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
4. Current address: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 01238, USA.

Correspondence to: Mike O'Donnell¹ Email: odonnel@mail.rockefeller.edu