A hybrid two-component system protein from Azospirillum brasilense Sp7 was involved in chemotaxis
A hybrid two-component system protein from Azospirillum brasilense Sp7 was involved in chemotaxis
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DOI：
10.1016/j.micres.2010.08.006
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发表时间：
2011-01-01
影响因子：
6.7
通讯作者：
Chen, Sanfeng
中科院分区：
文献类型：
--
作者：
Cui, Yanhua;Tu, Ran;Chen, Sanfeng
本文报道了巴西固氮螺菌SP7的org35的序列和功能分析，该基因最初被鉴定为能够在酵母-双杂交系统中与NIFA相互作用。Org35编码一个混合的双组分系统蛋白，包括N-末端的PAS结构域、C-末端的组氨酸激酶(HPK)结构域和反应调节(RR)结构域。为了确定Org35的功能，构建了PAS结构域缺失插入突变体[Sp7353]和互补菌株Sp7353C。与野生型相比，突变体的趋化性降低，而互补菌株与野生型相似。这些数据表明，巴西乳杆菌org35在趋化作用中发挥了关键作用。表达了含有org35不同结构域的变异体，并对这些结构域的功能进行了体外研究。体外磷酸化分析表明，Org35的HPK结构域具有自激酶活性，并且磷酸化的HPK能够将磷酸基团转移到RR结构域。结果表明，Org35是一种磷酸化通讯蛋白。(C)2010年爱思唯尔股份有限公司。版权所有。
We here report the sequence and functional analysis of org35 of Azospirillum brasilense Sp7, which was originally identified to be able to interact with NifA in yeast-two-hybrid system. The org35 encodes a hybrid two-component system protein, including N-terminal PAS domains, a histidine kinase (HPK) domain and a response regulator (RR) domain in C-terminal. To determine the function of the Org35, a deletion insertion mutant in PAS domain [named Sp7353] and a complemental strain Sp7353C were constructed. The mutant had reduced chemotaxis ability compared to that of wild-type, and the complemental strain was similar to the wildtype strain. These data suggested that the A. brasilense org35 played a key role in chemotaxis. Variants containing different domains of the org35 were expressed, and the functions of these domains were studied in vitro. Phosphorylation assays in vitro demonstrated that the HPK domain of Org35 possessed the autokinase activity and that the phosphorylated HPK was able to transfer phosphate groups to the RR domain. The result indicated Org35 was a phosphorylation-communicating protein. (C) 2010 Elsevier GmbH. All rights reserved.