On March 30th, a paper entitled " A transcriptional factor B paralog functions as an activator to DNA damage-responsive expression in archaea " was published online in Nucleic Acids Research. It was the achievement made by the Archaea Molecular Biology Research Group of HZAU. Doctoral student Feng Xu from College of Life Science and Technology is the first author, and Prof. She Qunxin is the corresponding author.

DNA damage response is the premise for organisms to maintain genetic stability. Although kinase-mediated DNA damage response in eukaryote and SOS response in bacteria have been widely studied, a few studies are on DNA Damage-responsive Expression in Archaea, whose mechanism needs to be revealed. Through the analysis of the DNA damage in Sulfolobus solfataricus, a crenarchaea, and transcriptome, the study revealed that genes involved in nucleotide excision repair are not expressed, but genes involved in DNA Homologous Recombination Repair slightly increase. Once DNA of crenarchaea are damaged, there will be a large cell aggregation to promote the transfer of DNA in cells. As homologous recombination is accelerated, the main repair mode for archaea to repair DNA is homologous recombination, which was proved in previous research.

The study first proved that the TFB3, a transcriptional factor B paralog, is global transcription factor mediating DNA damage response in archaea. Evidences also suggested that cells couldn’ t aggregate and no gene expression was detected after the DNA damage of TFB3 inactivated by gene deletion in Sulfolobus islandicus. Investigating the function of this gene in DNA damage response, researchers found TFB3 controls membrane protein and transport protein in most cases, which indicates that TFB3 specifically control the DNA transfer pathway. The further phylogenetic analysis showed that there is a coevolution between TFB3 and Ced（Crenarchaeal system for exchange of DNA）, providing fresh evidence of a close relation between TFB3 and DNA transfer. In this study, there are some other genes relating to DNA damage response which lay an important foundation for subsequent research.

Translator: Qi Yuhong

Proofreader: Wang Xiaoyan