Prakash Krishna, Tuteja Renu
Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
Parasitol Int. 2010 Jun;59(2):271-7. doi: 10.1016/j.parint.2010.02.003. Epub 2010 Feb 11.
Helicases catalyze the opening of nucleic acid duplexes and are implicated in many nucleic acid metabolic cellular processes that require single stranded DNA or reorganization of RNA structure. Previously we have reported that Plasmodium falciparum genome contains a number of DEAD box helicases. In the present study we report the cloning, expression and characterization of one of the novel members of DEAD box family from P. falciparum. Our results indicate that it is a homologue of Has1p from yeast and it contains DNA and RNA unwinding, nucleic acid-dependent ATPase and RNA binding activities. This enzyme can utilize all the nucleosidetriphosphates (NTPs) and deoxy nucleosidetriphosphates (dNTPs) for its unwinding activity. Using a truncated derivative of this protein we further report that the N-terminal region of the protein is essentially required for its activity. These studies suggest that besides the conserved helicase domain the highly variable N-terminal region also contributes in the activity of the protein.
解旋酶催化核酸双链的解开，并参与许多需要单链DNA或RNA结构重组的核酸代谢细胞过程。此前我们报道过恶性疟原虫基因组包含多个DEAD盒解旋酶。在本研究中，我们报告了来自恶性疟原虫的DEAD盒家族一个新成员的克隆、表达及特性分析。我们的结果表明它是酵母Has1p的同源物，并且它具有DNA和RNA解旋、核酸依赖性ATP酶以及RNA结合活性。这种酶能够利用所有的核苷三磷酸（NTP）和脱氧核苷三磷酸（dNTP）来进行其解旋活性。使用该蛋白的截短衍生物，我们进一步报道该蛋白的N端区域对其活性至关重要。这些研究表明，除了保守的解旋酶结构域之外，高度可变的N端区域也对该蛋白的活性有贡献。
