TY - JOUR
T1 - Ring-like nucleoid does not play a key role in radioresistance of Deinococcus radiodurans
AU - Gao, GuanJun
AU - Lu, HuiMing
AU - Yin, LongFei
AU - Hua, YueJin
N1 - Funding Information:
Received November 27, 2006; accepted February 27, 2007 doi: 10.1007/s11427-007-0061-x †Corresponding author (email: yjhua@zju.edu.cn) Supported by the National Basic Research Program of China (Grant No. 2004CB19604), the National Natural Science Foundation of China (Grant No. 30330020), and the National Science fund for Distinguished Young Scholars (Grant No. 30425038)
PY - 2007/8
Y1 - 2007/8
N2 - The conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance", has instigated lots of debates. In this study, according to the previous research of Pprl's crucial role in radioresistance of D. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type D. radiodurans R1 strain, pprf function-deficient mutant (YR1), and pprl function-complementary strains (YR1001, YR1002, and YR1004) before and after exposure to ionizing irradiation. Fluorescence microscopy images indicate: (1) the majority of nucleoid structures in radioresistant strain R1 cells exhibit the tightly packed ring-like morphology, while the pprl function-deficient mutant YR1 cells carrying predominate ring-like structure represent high sensitivity to irradiation; (2) as an extreme radioresistant strain similar to wild-type R1, pprl completely function-complementary strain YR1001 almost displays the loose and irregular nucleoid morphologies. On the other hand, another radioresistant pprl partly function-complementary strain YR1002's nucleiods exhibit about 60% ring-like structure; (3) a Pprl C-terminal deletion strain YR1004 consisting of approximately 60% of ring-like nucleoid is very sensitive to radiation. Therefore, our present experiments do not support the conclusion that the ring-like nucleoid of D. radiodurans does play a key role in radioresistance.
AB - The conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance", has instigated lots of debates. In this study, according to the previous research of Pprl's crucial role in radioresistance of D. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type D. radiodurans R1 strain, pprf function-deficient mutant (YR1), and pprl function-complementary strains (YR1001, YR1002, and YR1004) before and after exposure to ionizing irradiation. Fluorescence microscopy images indicate: (1) the majority of nucleoid structures in radioresistant strain R1 cells exhibit the tightly packed ring-like morphology, while the pprl function-deficient mutant YR1 cells carrying predominate ring-like structure represent high sensitivity to irradiation; (2) as an extreme radioresistant strain similar to wild-type R1, pprl completely function-complementary strain YR1001 almost displays the loose and irregular nucleoid morphologies. On the other hand, another radioresistant pprl partly function-complementary strain YR1002's nucleiods exhibit about 60% ring-like structure; (3) a Pprl C-terminal deletion strain YR1004 consisting of approximately 60% of ring-like nucleoid is very sensitive to radiation. Therefore, our present experiments do not support the conclusion that the ring-like nucleoid of D. radiodurans does play a key role in radioresistance.
KW - Deinococcus radiodurans R1
KW - Ionizing irradiation
KW - Radioresistance
KW - Ring-like nucleoid
KW - pprl
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U2 - 10.1007/s11427-007-0061-x
DO - 10.1007/s11427-007-0061-x
M3 - Article
C2 - 17653675
AN - SCOPUS:34547230142
SN - 1006-9305
VL - 50
SP - 525
EP - 529
JO - Science in China, Series C: Life Sciences
JF - Science in China, Series C: Life Sciences
IS - 4
ER -