Cloning and characterization of a thermostable superoxide dismutase from the thermophilic bacterium Rhodothermus sp. XMH10.
A superoxide dismutase (SOD) gene was cloned from the thermophilic bacterium Rhodothermus sp. XMH10 for the first time and highly expressed in Escherichia coli. The Rhodothermus sp. XMH10 SOD (RhSOD) gene encodes 209 amino acids with a putative molecular weight of 23.6 kDa and a pI value of 5.53. The recombinant RhSOD was detected to be an iron type SOD and existed as a dimer on its natural status. Experiments revealed that this RhSOD showed high activity at 50-70 degrees C and pH 5.0. Compared to SODs from other thermophiles, it was highly thermostable, maintaining more than 90% of its activity after incubation at 70 degrees C for 12 h, only totally inactivated after more than 4-h incubation at 80 degrees C. It also showed much higher resistance to KCN, NaN(3) and H(2)O(2) as compared to other SODs.
Wang
Xin
X
Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen, 361005, People's Republic of China.
Yang
Haijie
H
Ruan
Lingwei
L
Liu
Xin
X
Li
Fang
F
Xu
Xun
X
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003067:Coenzymes / Q000494:pharmacology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D019281:Dimerization; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000494:pharmacology; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D045245:Rhodothermus / Q000201:enzymology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000235:genetics*; D013696:Temperature
D003067:Coenzymes; D004269:DNA, Bacterial; D007501:Iron; D013482:Superoxide Dismutase