Expression of multiple tfb genes in different Halobacterium salinarum strains and interaction of TFB with transcriptional activator GvpE
Expression of multiple tfb genes in different Halobacterium salinarum strains and interaction of TFB with transcriptional activator GvpE
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DOI：
10.1007/s00203-011-0756-z
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发表时间：
2012-04-01
影响因子：
2.8
通讯作者：
Pfeifer, Felicitas
中科院分区：
文献类型：
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作者：
Bleiholder, Anne;Frommherz, Regina;Pfeifer, Felicitas
盐杆菌 NRC-1 含有多种 TBP 和 TFB 蛋白，这些蛋白是募集 RNA 聚合酶以启动转录所需的。在两种 Hbt 中研究了编码 TFB 的基因的存在和表达。盐藻菌株NRC-1和PHH1以及突变菌株PHH4。 PHH1和PHH4中缺乏NRC-1的质粒编码的tfbC和tfbE基因。 tfbF 转录物的 5'-末端经测定并含有 39 个核苷酸的 5'-非翻译区，能够形成茎环结构。在 15、37°C 和热休克条件下生长的培养物中研究了这些 tfb 基因的表达。寒冷的温度会减少生长，除了 tfbF 外，所有 tfb 转录本的数量也会减少。然而，PHH1 和 NRC-1 中气体囊泡的形成增加。热休克降低了 PHH1 和 NRC-1 的生长，但 PHH4 没有受到影响。在 PHH1 和 PHH4 中观察到 tfbA 和 tfbB mRNA 增加了 100 倍，而 NRC-1 减少了这些转录物的数量并增加了 tfbG 的表达。所有测试的 TFB 蛋白都能够与参与气体囊泡形成的转录激活剂 GvpE 相互作用，从而能够将 TFB 招募到 gvp 启动子上。
Halobacterium salinarum NRC-1 contains multiple TBP and TFB proteins required for the recruitment of RNA polymerase for transcription initiation. The presence and the expression of genes encoding TFB were investigated in the two Hbt. salinarum strains NRC-1 and PHH1 and the mutant strain PHH4. The plasmid-encoded tfbC and tfbE genes of NRC-1 were lacking in PHH1 and PHH4. The 5'-end of the tfbF transcript was determined and contained a 5'-untranslated region of 39 nucleotides able to form a stem-loop structure. The expression of these tfb genes was studied in cultures growing at 15, 37A degrees C and under heat shock conditions. Cold temperatures reduced growth and except for tfbF also the amounts of all tfb transcripts. However, the formation of gas vesicles increased in PHH1 and NRC-1. Heat shock reduced growth of PHH1 and NRC-1, but PHH4 was not affected. A 100-fold increase in tfbA and tfbB mRNA was observed in PHH1 and PHH4, whereas NRC-1 reduced the amounts of these transcripts and increased the expression of tfbG. All TFB proteins tested were able to interact with the transcription activator GvpE involved in gas vesicle formation that thus is able to recruit TFB to the gvp promoter.