Preliminary characterization of a thermostable DNA polymerase I from a mesophilic Bacillus sphaericus strain C3-41.
A thermostable DNA polymerase I from a mesophilic Bacillus sphaericus strain C3-41 was characterized in this study. The polI was cloned, sequenced and over-expressed in Escherichia coli. The expressed 110 kDa fusion protein of PolI was stable at 70 degrees C for 1 h. Compared with DNA polymerase I of E. coli (TaKaRa), the relative polymerase activity of this PolI was 3.33 +/- 0.1 RFU microl(-1) at 37 degrees C using fluorescent quantitative analysis. It showed higher polymerase activity than E. coli PolI at higher temperature, with a relative activity of 3.75 +/- 0.1 RFU microl(-1) at 70 degrees C. The polI sequence analysis and the protein structure prediction indicated that this protein had a high similarly to other PolI from thermophilic micro-organisms. This information is of importance for future study for evolution of the house-keeping gene polI in entomopathogenic bacterium B. sphaericus.
Bei
Han
H
Wuhan Institute of Virology, Chinese Academy of Science, Wuhan 430071, China.
Haizhou
Liu
L
Xiaomin
Hu
H
Zhiming
Yuan
Y
D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004256:DNA Polymerase I / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D011994:Recombinant Proteins; D004256:DNA Polymerase I