Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Escherichia coli Y family DNA polymerases
DNA damage is ubiquitous, arising from both environmental and endogenous sources. All organisms have evolved multiple pathways to respond to DNA damage and maintain genomic integrity. Escherichia coli possesses two DNA polymerases, pol IV and pol V, that are members of the Y family. These polymerases are characterized by their specialized ability to copy damaged DNA as well as their relatively low fidelity on undamaged DNA. Pol IV and pol V are regulated by the SOS response to DNA damage and by their multiple interactions with other proteins. These two Y family DNA polymerases copy DNA damaged by distinct agents. Pol IV is capable of replicating DNA containing N2-dG adducts, while pol V bypasses abasic sites and thymine-thymine dimers, which result from exposure to UV radiation. In addition to their roles in copying damaged DNA, the two Y family DNA polymerases in E. coli act in regulation of DNA replication and contribute to bacterial mutagenesis in response to cellular stress.