Part:BBa_K2195000

Dsup (Radiation Protection)

Dsup is a protein that helps protect DNA from radiation damage. It was discovered in the Tardigrade Species Ramazzottius Varieornatus. Dsup was discovered to protect this tardigrade species from X-ray damage [1]. Since only X-ray damage was tested, we decided to test if Dsup can protect organisms from UV radiation as well since it was not theorized to be a repair mechanism.

Usage and Biology

We found that Dsup can protect DH5α E. coli from UV-B radiation that normally causes pyrimidine dimers in the DNA. Using our UV irradiation protocol, we found that E. coli cells with the Dsup gene had a lower death rate/higher survival rate than our control cells.

The cells that were transformed to contain Dsup were found to have significantly higher survival rates than those without Dsup. Overall, cells containing Dsup--both induced and uninduced--showed an average survival rate of approximately 26% after four hours of exposure to UV-B radiation, while the cells containing only blue chromoprotein (without any radiation resistance genes) showed a survival rate of 0% after four hours. The most pronounced difference between cells containing Dsup and cells containing no radiation resistance was found at three hours, with Dsup-containing cells having an average survival rate of 49% and non-Dsup-containing cells having an average survival rate of 2.3%, meaning that cells with Dsup survived at a rate that was, on average, 2130% higher than the rate at which non-Dsup cells survived.

There was no significant difference observed in the survival rates of cells in which expression of Dsup was induced via addition of IPTG and cells in which it was not induced, indicating extremely leaky expression in the Lac promoter.

Contribution Markup

Group:SJTU-Biox-Shanghai；

Author: Saiya Li Zhouyu Lu；

Summary：The DNA protection ability and biological stress resistance were improved by directed evolution.The suitable mutation sites were found by software simulation.

Fig. 3 DSUP orientation simulation results.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 240
  Illegal BamHI site found at 694
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]