The crystal and solution structure of a putative transcriptional antiterminator from Mycobacterium tuberculosis
The crystal and solution structure of a putative transcriptional antiterminator from Mycobacterium tuberculosis
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DOI：
10.1016/j.str.2004.06.018
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发表时间：
2004-09-01
期刊：
影响因子：
5.7
通讯作者：
Tucker, PA
中科院分区：
文献类型：
--
作者：
Morth, JP;Feng, V;Tucker, PA
我们描述了结核分枝杆菌Rv1626在1.48埃分辨率下的晶体结构和由小角X射线散射确定的相应的溶液结构。N-末端结构域显示出与细菌双组分系统中发现的接收器结构域的结构同源性。C-末端结构域与最近发现的参与转录抗终止的RNA结合域具有高度的结构同源性。溶液中的分子被发现是单体，因为它在晶体中，但在溶液中，它经历了由离子强度变化引发的构象变化。这是第一个将双组分系统的磷酸化级联与转录机制中的抗终止事件联系起来的结构。Rv1626属于一个蛋白质家族，我们建议将其称为磷酸化依赖的转录抗终止调节因子，到目前为止只在细菌中发现，其中包括来自棕色固氮杆菌同化硝酸盐/亚硝酸盐还原酶操纵子的蛋白Nast。
We describe the crystal structure of Rv1626 from Mycobacterium tuberculosis at 1.48 Angstrom resolution and the corresponding solution structure determined from small angle X-ray scattering. The N-terminal domain shows structural homology to the receiver domains found in bacterial two-component systems. The C-terminal domain has high structural homology to a recently discovered RNA binding domain involved in transcriptional antitermination. The molecule in solution was found to be monomeric as it is in the crystal, but in solution it undergoes a conformational change that is triggered by changes in ionic strength. This is the first structure that links the phosphorylation cascade of the two-component systems with the antitermination event in the transcriptional machinery. Rv1626 belongs to a family of proteins, which we propose calling phosphorylation-dependent transcriptional antitermination regulators, so far only found in bacteria, and includes NasT, a protein from the assimilatory nitrate/nitrite reductase operon of Azetobacter vinelandii.