Brooun A, Bell J, Freitas T, Larsen R W, Alam M
Department of Microbiology, University of Hawaii, Honolulu 96822, USA.
J Bacteriol. 1998 Apr;180(7):1642-6. doi: 10.1128/JB.180.7.1642-1646.1998.
Signal transduction in the archaeon Halobacterium salinarum is mediated by three distinct subfamilies of transducer proteins. Here we report the complete htrVIII gene sequence and present analysis of the encoded primary structure and its functional features. HtrVIII is a 642-amino-acid protein and belongs to halobacterial transducer subfamily B. At the N terminus, the protein contains six transmembrane segments that exhibit homology to the heme-binding sites of the eukaryotic cytochrome c oxidase. The C-terminal domain has high homology with the eubacterial methyl-accepting chemotaxis protein. The HtrVIII protein mediates aerotaxis: a strain with a deletion of the htrVIII gene loses aerotaxis, while an overproducing strain exhibits stronger aerotaxis. We also demonstrate that HtrVIII is a methyl-accepting protein and demethylates during the aerotaxis response.
嗜盐古菌盐生盐杆菌中的信号转导由三种不同的转导蛋白亚家族介导。在此,我们报告完整的htrVIII基因序列,并对编码的一级结构及其功能特征进行分析。HtrVIII是一种含有642个氨基酸的蛋白质,属于盐杆菌转导蛋白亚家族B。在N端,该蛋白质包含六个跨膜片段,与真核细胞色素c氧化酶的血红素结合位点具有同源性。C端结构域与真细菌甲基接受趋化蛋白具有高度同源性。HtrVIII蛋白介导趋氧性:htrVIII基因缺失的菌株失去趋氧性,而过表达菌株表现出更强的趋氧性。我们还证明HtrVIII是一种甲基接受蛋白,在趋氧性反应过程中会发生去甲基化。