Kutuzov M A, Evans D E, Andreeva A V
Research School of Biological and Molecular Sciences, Oxford Brookes University, Headington, UK.
FEBS Lett. 1998 Nov 27;440(1-2):147-52. doi: 10.1016/s0014-5793(98)01428-8.
We have recently identified an Arabidopsis thaliana cDNA encoding a putative protein Ser/Thr phosphatase PP7, not closely related to any protein phosphatases in animals or fungi. Here, we describe the characterization of PP7 expressed in a bacterial system. The recombinant protein was inactive unless the longest insert in its catalytic domain was cleaved, suggesting that this insert is an autoinhibitory region. PP7 was resistant to okadaic acid, calyculin and fumonisin B1, and was stimulated by Mn2+ or Fe2+, while Ni2+ and Zn2+ were inhibitory. Polylysine stimulated PP7 activity towards p-nitrophenylphosphate but inhibited activity towards the most efficient protein substrate, myelin basic protein. A tentative model of the control of PP7 activity is proposed.
我们最近鉴定出拟南芥的一个编码假定蛋白丝氨酸/苏氨酸磷酸酶PP7的cDNA，它与动物或真菌中的任何蛋白磷酸酶都没有密切关系。在此，我们描述了在细菌系统中表达的PP7的特性。重组蛋白无活性，除非其催化结构域中最长的插入片段被切割，这表明该插入片段是一个自抑制区域。PP7对冈田酸、花萼海绵诱癌素和伏马菌素B1具有抗性，并受到Mn2+或Fe2+的刺激，而Ni2+和Zn2+则具有抑制作用。聚赖氨酸刺激PP7对对硝基苯磷酸酯的活性，但抑制对最有效的蛋白质底物髓鞘碱性蛋白的活性。我们提出了一个控制PP7活性的初步模型。
