A novel arginine kinase from the shrimp Neocaridina denticulata: The fourth arginine kinase gene lineage
A novel arginine kinase from the shrimp Neocaridina denticulata: The fourth arginine kinase gene lineage
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DOI：
10.1016/j.gene.2009.02.018
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发表时间：
2009-05-15
期刊：
影响因子：
3.5
通讯作者：
Suzuki, Tomohiko
中科院分区：
文献类型：
--
作者：
Iwanami, Kentaro;Iseno, Shin-ichi;Suzuki, Tomohiko
精氨酸激酶（AK）独立地进化至少三次：第一次在磷酸原激酶进化的早期阶段（典型AK），第二次从细胞质肌酸激酶（CK）基因后来在后生动物进化（海参AK）和第三次从线粒体CK基因在环节动物辐射过程中（Sabellastarte AK）。在这里，我们提出了一个可能的第四AK血统。本研究从齿状新米虾（Neocaridina denticulata）中扩增了3种AKs（AK 1、AK 2和AK 3）的cDNA，并测定了它们的氨基酸序列（355-356残基）。将每个cDNA序列克隆到pET质粒中，并在大肠杆菌中表达相应的重组激酶。杆菌AK在分析凝胶过滤柱上显示出与典型AK相似的单体性质。虽然AK 2的氨基酸序列对应于典型AK的chat，包含在鲎AK中建立的底物结合位点的保守关键残基，但AK 1和AK 3的氨基酸序列缺乏这些关键残基中的一些，表明与海参和Sabellastarte AK相似的进化。此外，系统发育分析的磷酸原激酶表明，新米虾AK 1和AK 3分歧在最深的分支点接近的根的自由，并形成了一个独特的集群外的典型AK集群，其中包括新米虾AK 2。动力学常数与其他AKs相似。然而，AK 1和AK 3的过渡态的活化能（E（a））比AK 2的大约1.5倍。AK 1和AK 3的Δ H度（双匕首）值也比AK 2大约1.5倍，但所有三个Δ H度（双匕首）值都非常相似（71-72 kJ/mol）：这导致三个AK反应的相似反应速度，这是由于与AK 2相比，AK 1和AK 3反应的活化复合物中的熵降低较低。这些发现表明，新米虾属AK 1和AK 3是已知的三个AK基因谱系中唯一的，因此构成了第四个AK谱系。(C)2009 Elsevier B. V.保留所有权利。
Arginine kinases (AK) evolved independently at least three times: first at an early stage of phosphagen kinase evolution (typical AK), second from the cytoplasmic creatine kinase (CK) gene later in metazoan evolution (Stichopus AK) and third from the mitochondrial CK gene in the course of annelid radiation (Sabellastarte AK). Here, we present a possible fourth AK lineage. We amplified cDNA encoding three AKs (AK1, AK2 and AK3) from the shrimp Neocaridina denticulata, and determined their amino acid sequences (355-356 residues). Each cDNA sequence was cloned in a pET plasmid and the corresponding recombinant kinase was expressed in E. coli. The AKs showed monomeric nature Similar to typical AKs on an analytical gel filtration Column. While the amino acid sequence of AK2 corresponded to chat of typical AK, containing the conserved key residues established in Limulus AK for the substrate binding site, those of AK1 and AK3 lacked some of these key residues, indicating a similar evolution to Stichopus and Sabellastarte AKs. Moreover, phylogenetic analysis of phosphagen kinases indicated that Neocaridina AK1 and AK3 diverged at the deepest branching point close to the root of the free and formed a distinct cluster outside the typical AK Cluster, which included Neocaridina AK2. Kinetic constants of Neocaridina AKs were similar to those of other AKs. However, activation energy (E(a)) for the transition state of AK1 and AK3 was about 1.5-fold larger than that of AK2. The Delta H degrees(double dagger) values for AK1 and AK3 were also about 1.5-fold larger than that for AK2, but all three Delta H degrees(double dagger) values were very similar (71-72 kJ/mol): this results in similar reaction velocities for the three AK reactions due to a lower decrease in entropy in the activated complexes of AK1 and AK3 reactions Compared to that of AK2. These findings Suggest that Neocaridino AK1 and AK3 ate unique from the known three AK gene lineages and therefore comprises a fourth AK lineage. (C) 2009 Elsevier B.V. All rights reserved.