The transcriptional activator GvpE for the halobacterial gas vesicle genes resembles a basic region leucine-zipper regulatory protein
The transcriptional activator GvpE for the halobacterial gas vesicle genes resembles a basic region leucine-zipper regulatory protein
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DOI：
10.1006/jmbi.1998.1795
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发表时间：
1998-06-19
影响因子：
5.6
通讯作者：
Pfeifer, F
中科院分区：
文献类型：
--
作者：
Krüger, K;Hermann, T;Pfeifer, F
GvpE蛋白参与了嗜盐古菌气体囊泡合成的调控，已被确定为gvpA基因上游启动子的转录激活子，该启动子编码主要的气体囊泡结构蛋白gvpA。对GvpE蛋白序列的进一步研究表明，GvpE类似于真核生物基因调控中典型的亮氨酸拉链蛋白。c末端的分子模型研究表明，一簇碱性氨基酸残基构成了dna结合位点（DNAB），随后是一个两亲性螺旋，适合在GvpE二聚体中形成亮氨酸拉链结构。GvpE二聚体停靠在DNA上的模型表明，碱性残基的侧链可以完美地与DNA主链的带负电荷的磷酸基团相互作用。用丙氨酸和/或谷氨酸取代这个假定的DNAB的三个碱性氨基酸残基产生突变的GvpE蛋白。这些都不能在体内激活c-gvpA启动子，这表明这些基本残基是GvpE活性所必需的。古生菌基因调控因子与真核调控蛋白的相似性表明，真核菌和古生菌的基本转录机制密切相关，调控蛋白根据共同的原理进化。(C) 1998学术出版社有限公司
The GvpE protein involved In the regulation of gas vesicles synthesis in halophilic archaea has been identified as the transcriptional activator for the promoter located upstream of the gvpA gene encoding the major gas vesicle structural protein GvpA. A closer inspection of the GvpE protein sequence revealed that GvpE resembles basic leucine-zipper proteins typically involved in the gene regulation of eukarya. A molecular modelling study of the C-terminal part implied a cluster of basic amino acid residues constituting the DNA-binding site (DNAB) followed by an amphiphilic helix, suitable for the formation of a leucine-zipper structure within a GvpE dimer. The model of a GvpE dimer docked onto DNA indicated that the side-chains of the basic residues could perfectly interact with the negatively charged phosphate groups of the DNA backbone. Substitution of three basic amino acid residues of this putative DNAB by alanine and/or glutamate generated mutated GvpE proteins. None of these was able to activate the c-gvpA promoter in vivo, indicating that these basic residues are required for GvpE activity. This identification of an archaeal gene regulator displaying similarity to eukaryal regulatory proteins implies that the basic transcription machinery of eukarya and archaea are closely related, and that the regulatory proteins have evolved according to common principles. (C) 1998 Academic Press Limited.