Ringlike structure of the Deinococcus radiodurans genome: a key to radioresistance?
The bacterium Deinococcus radiodurans survives ionizing irradiation and other DNA-damaging assaults at doses that are lethal to all other organisms. How D. radiodurans accurately reconstructs its genome from hundreds of radiation-generated fragments in the absence of an intact template is unknown. Here we show that the D. radiodurans genome assumes an unusual toroidal morphology that may contribute to its radioresistance. We propose that, because of restricted diffusion within the tightly packed and laterally ordered DNA toroids, radiation-generated free DNA ends are held together, which may facilitate template-independent yet error-free joining of DNA breaks.
Levin-Zaidman
Smadar
S
Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
Englander
Joseph
J
Shimoni
Eyal
E
Sharma
Ajay K
AK
Minton
Kenneth W
KW
Minsky
Abraham
A
D002843:Chromatin / Q000648:ultrastructure; D003037:Cobalt Radioisotopes; D004249:DNA Damage; D004260:DNA Repair; D004269:DNA, Bacterial / Q000032:analysis / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure*; D034301:Deinococcus / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects* / Q000648:ultrastructure; D016680:Genome, Bacterial; D008345:Manganese / Q000378:metabolism; D017895:Manganese Compounds / Q000494:pharmacology; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009690:Nucleic Acid Conformation; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D011938:Rec A Recombinases / Q000378:metabolism; D011995:Recombination, Genetic; D013431:Sulfates / Q000494:pharmacology; D013698:Templates, Genetic; D014466:Ultraviolet Rays
D002843:Chromatin; D003037:Cobalt Radioisotopes; D004269:DNA, Bacterial; D017895:Manganese Compounds; D013431:Sulfates; D008345:Manganese; D011938:Rec A Recombinases; C039798:manganese sulfate