毒死蜱降解菌腺苷酸激酶基因的分离及结构特征

Cloning and structure feature of adenylate kinase gene from a degrading strain of chlorpyrifos

本研究以1株有机磷农药毒死蜱的降解菌施氏假单胞菌(Pseudomonas stutzeri)75为研究材料,从该菌基因组中克隆到腺苷酸激酶(adenylate kinase,ADK)基因。序列长810 bp,包含完整的ADK基因编码区648 bp,编码215个氨基酸组成的ADK75蛋白。经比对分析,施氏假单胞菌75的ADK基因与假单胞菌属的相应基因相似性最高达99.5%;对ADK75的二级和三级结构分析结果显示,ADK75蛋白具有典型的腺苷酸激酶结构特点,与同属的ADK蛋白相比,AMPbd结构域和LID结构域分别有3～13与5～16个氨基酸差异,这些氨基酸变化可能与施氏假单胞菌75能够以毒死蜱作为唯一碳源生长的代谢特点有关。

The adenylate kinase （ADK） gene was amplified from an isolated strain Pseudomonas stutzeri 75 with ability to degrade organophosphorus pesticides, chlorpyrifos. The sequence of ADK75 gene was 810 bp in length and contained completed open reading frame （ORF） of 648 bp which encoded a polypeptide of 215 amino acids. After comparing with known sequences deposited in the GenBank, the highest homology of ADK75 gene was 99.5 %. Furthermore, the secondary and tertiary structures of ADK75 protein were analyzed. A typical ADK structure was found in the P. stutzeri strain 75 with three subdomains, that was AMP-binding subdomain （AMPbd）, ATP-binding subdomain （LID）, and the core subdomain. There were 3-13 and 5-16 amino acids substitution in AMPbd and LID, respectively. These changes might infer to be correlated with the characteristics of P. stutzeri strain 75 taking the chlorpyrifos as exclusive carbohy- drate sources.