EheA from Exiguobacterium sp. yc3 is a novel thermostable DNase belonging to HNH endonuclease superfamily.
The HNH endonuclease superfamily usually contains a conserved HNH motif in the sequence, and the second subfamily of it uses N to replace the second H in the HNH motif. A bacterium with extracellular thermostable DNase was isolated and identified as Exiguobacterium sp. yc3. A 20 kDa putative DNase was later purified and the encoding gene of it was amplified and sequenced, the deduced amino acid sequence analysis showed that the protein belongs to the HNH endonuclease superfamily, and therefore it was named as EheA ( E: xiguobacterium H: NH E: ndonuclease). Characterization of the recombinant EheA confirmed that EheA is a DNase. By site-directed mutation method, H116, N141 and N156 were proved to be essential for the DNase activity. EheA is the first experimentally determined bacterial source endonuclease belonging to the second subfamily of HNH superfamily. Further bioinformatic analysis showed that EheA homologue genes are conserved in the Exiguobacterium species, which suggests their possible important functions for Exiguobacterium species. And as a thermostable DNase, EheA also has a promising future in many application fields.
Key Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China, 210095.
Hanying
H
Zhou
Key Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China, 210095.
Pengpeng
P
Li
Key Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China, 210095.
Dongxia
D
Wu
Key Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China, 210095.
Tingting
T
Ran
Key Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China, 210095.
Weiwu
W
Wang
Key Laboratory of Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, China, 210095 dqxu@njau.edu.cn.
Dongqing
D
Xu
D000595:Amino Acid Sequence; D056449:Bacillales / Q000201:enzymology* / Q000235:genetics; D019295:Computational Biology; D004706:Endodeoxyribonucleases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D004795:Enzyme Stability; D016680:Genome, Bacterial; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010802:Phylogeny; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017422:Sequence Analysis, DNA
D011994:Recombinant Proteins; D004706:Endodeoxyribonucleases
EheA; Exiguobacterium; HNH endonuclease superfamily; deoxyribonuclease (DNase); protein purification; thermostable