title: Identification and evaluation of the role of the manganese efflux protein in Deinococcus radiodurans.
abstract: BACKGROUND
  Deinococcus radiodurans accumulates high levels of manganese ions, and this is believed to be correlated with the radiation resistance ability of this microorganism. However, the maintenance of manganese ion homeostasis in D. radiodurans remains to be investigated.
  
  
  RESULTS
  In this study, we identified the manganese efflux protein (MntE) in D. radiodurans. The null mutant of mntE was more sensitive than the wild-type strain to manganese ions, and the growth of the mntE mutant was delayed in manganese-supplemented media. Furthermore, there was a substantial increase in the in vivo concentration of manganese ions. Consistent with these characteristics, the mntE mutant was more resistant to H2O2, ultraviolet rays, and γ-radiation. The intracellular protein oxidation (carbonylation) level of the mutant strain was remarkably lower than that of the wild-type strain.
  
  
  CONCLUSIONS
  Our results indicated that dr1236 is indeed a mntE homologue and is indispensable for maintaining manganese homeostasis in D. radiodurans. The data also provide additional evidence for the involvement of intracellular manganese ions in the radiation resistance of D. radiodurans.
authors.affiliation: Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, 310029, Hangzhou, PR China. yjhua@zju.edu.cn
authors.forename: Hongxing
authors.initials: H
authors.lastname: Sun
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Xu
authors.forename: Hongdan
authors.initials: H
authors.lastname: Zhan
authors.forename: Huan
authors.initials: H
authors.lastname: Chen
authors.forename: Zongtao
authors.initials: Z
authors.lastname: Sun
authors.forename: Bing
authors.initials: B
authors.lastname: Tian
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Hua
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D034301:Deinococcus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D005720:Gamma Rays; D006861:Hydrogen Peroxide / Q000378:metabolism; D008345:Manganese / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D016415:Sequence Alignment; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D008345:Manganese; D006861:Hydrogen Peroxide