Primary structure and functional analysis of the soluble transducer protein HtrXI in the archaeon Halobacterium salinarium
Primary structure and functional analysis of the soluble transducer protein HtrXI in the archaeon Halobacterium salinarium
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DOI：
10.1128/jb.179.9.2963-2968.1997
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发表时间：
1997-05-01
影响因子：
3.2
通讯作者：
Alam, M
中科院分区：
文献类型：
--
作者：
Brooun, A;Zhang, WS;Alam, M
盐盐古细菌中的信号转导是由13个可溶性和膜结合的转导器家族介导的。在这里，我们报道了最小的假定盐细菌传感器之一HtrXI的初级结构和功能分析，初级结构的亲水图分析预测HtrXI中没有跨膜片段，H，盐蛋白的分离证实HtrXI是一种可溶性蛋白。HtrXI缺失突变体和补充菌株的毛细管实验表明，这种可溶性换能器参与了对Asp和Glu的趋化。对HtrXI -1缺失突变体的体内甲基酯酶活性分析表明，HtrXI在盐细菌对His、Asp和Glu的趋化反应的适应中发挥了重要作用，这是盐细菌的引诱剂，Asp和Glu的刺激导致HtrXI和另一种可能的换能器HtrVII去甲基化。但在盐杆菌细胞中加入His会增加HtrXI和其他可能的传感器的甲基化。在缺乏HtrXI的情况下，Glu或His的刺激不会降低或增加任何假定的转导器的甲基化。因此，HtrXI传感器似乎在趋化性信号转导中具有复杂的作用。
Signal transduction in the archaeon Halobacterium salinarium is mediated by a family of 13 soluble and membrane-bound transducers. Here, we report the primary structure and functional analysis of one of the smallest halobacterial putative transducers, HtrXI, Hydropathy plot analysis of the primary structure predicts no membrane-spanning segments in HtrXI, The fractionation of the H, salinarium proteins confirmed that HtrXI is a soluble protein. Capillary assay with an HtrXI deletion mutant and a complemented strain revealed that this soluble transducer is involved in Asp and Glu taxis, In vivo analysis of the methylesterase activity of the htrXI-1 deletion mutant suggests that HtrXI plays an important role in the adaptation of the chemotactic responses to His, Asp, and Glu, which are attractants for halobacteria, Stimulation by Asp and Glu causes demethylation of HtrXI and of another putative transducer, HtrVII, But addition of His to halobacterial cells increases HtrXI methylation together with that of other putative transducers. In the absence of HtrXI, stimulation by either Glu or His does not decrease or increase the methylation of any putative transducers. Therefore, the HtrXI transducer appears to have a complex role in chemotaxis signal transduction.