Biochemical characterization of a thermostable HNH endonuclease from deep-sea thermophilic bacteriophage GVE2----中国科学院微生物研究所

科研成果

论文题目:	Biochemical characterization of a thermostable HNH endonuclease from deep-sea thermophilic bacteriophage GVE2
作者:	Zhang, Likui Huang, Yanchao Xu, Dandan Yang, Lixiang Qian, Kaicheng Chang, Guozhu Gong, Yong Zhou, Xiaojian Ma, Kesen
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刊物名称:	Applied Microbiology and Biotechnology
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年份:	2016
影响因子:	3.882
论文下载:	http://link.springer.com/article/10.1007%2Fs00253-016-7568-7
摘要:	His-Asn-His (HNH) proteins are a very common family of small nucleic acid-binding proteins that are generally associated with endonuclease activity and are found in all kingdoms of life. Although HNH endonucleases from mesophiles have been widely investigated, the biochemical functions of HNH endonucleases from thermophilic bacteriophages remain unknown. Here, we characterized the biochemical properties of a thermostable HNH endonuclease from deep-sea thermophilic bacteriophage GVE2. The recombinant GVE2 HNH endonuclease exhibited non-specific cleavage activity at high temperature. The optimal temperature of the GVE2 HNH endonuclease for cleaving DNA was 60-65 A degrees C, and the enzyme retained its DNA cleavage activity even after heating at 100 A degrees C for 30 min, suggesting the enzyme is a thermostable endonuclease. The GVE2 HNH endonuclease cleaved DNA over a wide pH spectrum, ranging from 5.5 to 9.0, and the optimal pH for the enzyme activity was 8.0-9.0. Furthermore, the GVE2 HNH endonuclease activity was dependent on a divalent metal ion. While the enzyme is inactive in the presence of Cu2+, the GVE2 HNH endonuclease displayed cleavage activity of varied efficiency with Mn2+, Mg2+, Ca2+, Fe2+, Co2+, Zn2+, and Ni2+. The GVE2 HNH endonuclease activity was inhibited by NaCl. This study provides the basis for determining the role of this endonuclease in life cycle of the bacteriophage GVE2 and suggests the potential application of the enzyme in molecular biology and biotechnology.