The LexA‐regulated gene ybfE plays a role in DNA metabolism in E. coli

Abstract

DNA is constantly exposed to damage‐causing agents. The SOS DNA damage response in Escherichia coli is regulated by the LexA protein, and controls the expression of more than 50 different genes. One of the many genes regulated by the SOS response encodes the uncharacterized protein YbfE. Previous work in our lab has shown ybfE is essential to cell survival after exposure to alkylating agents. In order to characterize ybfE further, two open reading frames are being examined because two different in vitro transcription start sites have been proposed. One open reading frame encodes an additional 23 amino acids at the N‐terminus of the protein and has been shown to cause a striking decrease in cell survival upon overexpression. To Identify genetic interactions, a series of knockout strains have been investigated to determine whether deletion of any one gene alleviates the lethality associated with overexpression of ybfE. To date assays in strains harboring deletions of various DNA repair proteins have not suppressed the lethal overexpression phenotype. In addition, hydroxyurea sensitivity studies are being conducted. Hydroxyurea is known to inhibit DNA replication without inducing DNA damage, allowing further investigation into the role ybfE plays in the SOS response. Deletion of the ybfE gene reduces the susceptibility of wild‐type E. coli to HU suggesting a role for YbfE in DNA metabolism. Further investigation into protein interactions and the role of YbfE in the SOS response are ongoing.Support or Funding InformationSupport from NSF‐MCB‐1615946 and American Cancer Society RSG‐12‐161‐01‐DMC.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.