Low-fidelity DNA polymerases

Low-fidelity DNA polymerases

Also known as.... Translesion synthesis polymerases. There are two of them in Escherichia coli, polymerases IV and V, and five in human cells, polymerases ζ, η, ι, κ and Rev1 (so a knowledge of the Greek alphabet is essential when discussing them). Except for polymerase ζ, they fall into a new DNA polymerase family, designated the Y-family. Depending on the lesion, polymerase and context, they ...

Fidelity of DNA polymerases in DNA amplification.

Denaturing gradient gel electrophoresis (DGGE) was used to separate and isolate the products of DNA amplification by polymerase chain reaction (PCR). The strategy permitted direct enumeration and identification of point mutations created by T4, modified T7, Klenow fragment of polymerase I, and Thermus aquaticus (Taq) DNA polymerases. Incorrectly synthesized sequences were separated from the wil...

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 cond...

Regulation and Fidelity: A study of RNA and DNA polymerases

A reexamination of the nucleotide incorporation fidelity of DNA polymerases.

Intensive study has been devoted to understanding the kinetic and structural bases underlying the exceptionally high fidelity (low error frequencies) of the typical DNA polymerase. Commonly proposed explanations have included (i) the concept of fidelity check points, in which the correctness of a nascent base pair match is tested at multiple points along the reaction pathway, and (ii) an induce...