A sliding-clamp toolbelt binds high- and low-fidelity DNA polymerases simultaneously.
This report demonstrates that the beta sliding clamp of E. coli binds two different DNA polymerases at the same time. One is the high-fidelity Pol III chromosomal replicase and the other is Pol IV, a low-fidelity lesion bypass Y family polymerase. Further, polymerase switching on the primed template junction is regulated in a fashion that limits the action of the low-fidelity Pol IV. Under conditions that cause Pol III to stall on DNA, Pol IV takes control of the primed template. After the stall is relieved, Pol III rapidly regains control of the primed template junction from Pol IV and retains it while it is moving, becoming resistant to further Pol IV takeover events. These polymerase dynamics within the beta toolbelt complex restrict the action of the error-prone Pol IV to only the area on DNA where it is required.
Indiani
Chiara
C
Laboratory of DNA Replication, The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
McInerney
Peter
P
Georgescu
Roxana
R
Goodman
Myron F
MF
O'Donnell
Mike
M
D004258:DNA Polymerase III / Q000378:metabolism*; D019951:DNA Polymerase beta / Q000378:metabolism*; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D046911:Macromolecular Substances; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation
D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D004258:DNA Polymerase III; D019951:DNA Polymerase beta