Abstract

The extremophilic bacterium Deinococcus radiodurans exhibits an extraordinary resistance to ionizing radiation. Previous studies established that a protein named PprI, which exists only in the Deinococcus-Thermus family, acts as a general switch to orchestrate the expression of a number of DNA damage response (DDR) proteins involved in cellular radio-resistance. Here we show that the regulatory mechanism of PprI depends on its Mn(2+)-dependent protease activity toward DdrO, a transcription factor that suppresses DDR genes’ expression. Recognition sequence-specificity around the PprI cleavage site is essential for DNA damage repair in vivo. PprI and DdrO mediate a novel DNA damage response pathway differing from the classic LexA-mediated SOS response system found in radiation-sensitive bacterium Escherichia coli. This PprI-mediated pathway in D. radiodurans is indispensable for its extreme radio-resistance and therefore its elucidation significantly advances our understanding of the DNA damage repair mechanism in this amazing organism.

Highlights

  • DNA repair is an essential process for cells to maintain their genomic stability

  • This is interesting as D. radiodurans was found to accumulate high concentration of Mn(2+) in the cell [16], which was suggested to be important for protection of protein against free radical created by radiation

  • PprI protein has been implicated as a switch for DNA damage response

Read more

Summary

Introduction

DNA repair is an essential process for cells to maintain their genomic stability. Cells have evolved elaborate systems to recover its DNA from damage caused by hazardous environmental stresses. The Gram-positive bacterium Deinococcus radiodurans is one of the commonly used model organism for studying DNA repair due to its exceptional tolerance to extensive DNA damage inflicted by various DNA-damaging agents such as ionizing radiation (IR), ultraviolet light (UV), chemical mutagens and desiccation [1,2,3,4]. Characterization of Proteolytic Properties of PprI no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call