Mechanistic insights revealed by the crystal structure of a histidine kinase with signal transducer and sensor domains.
Mechanistic insights revealed by the crystal structure of a histidine kinase with signal transducer and sensor domains.
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具有信号转换器和传感器域的组氨酸激酶晶体结构揭示的机制见解
DOI：
10.1371/journal.pbio.1001493
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发表时间：
2013
期刊：
影响因子：
9.8
通讯作者：
Han A
中科院分区：
文献类型：
--
作者：
Wang C;Sang J;Wang J;Su M;Downey JS;Wu Q;Wang S;Cai Y;Xu X;Wu J;Senadheera DB;Cvitkovitch DG;Chen L;Goodman SD;Han A
一个晶体结构揭示了一个优雅的机械开关，螺旋弯曲和催化结构域旋转允许在细菌应激反应过程中的组氨酸激酶的自激活。双组分系统（TCSs）对于细菌和真菌在胁迫条件下的适应和存活是重要的。TCS通常由膜结合传感器组氨酸激酶（SK）和反应调节剂（RR）组成，它们通过顺序磷酸化步骤进行中继。然而，SK如何响应环境刺激而打开的机制仍然不清楚。在这里，我们报告的晶体结构的一个完整的细胞质部分的SK，VicK从变形链球菌。VicK的总体结构是锚定四个连接结构域的长杆二聚体：HAMP、Per-ARNT-SIM（PAS）、DHp以及催化和ATP结合结构域（CA）。作为信号转导器的HAMP和作为主要传感器的PAS域采用具有二分体对称性的正则折叠。相比之下，DHp和CA结构域的二聚体是不对称的，因为DHp结构域中的不同螺旋弯曲和CA结构域的空间位置。此外，一个保守的脯氨酸，这是相邻的磷酰基受体组氨酸，有助于螺旋弯曲，这是必不可少的自激酶和磷酸酶的活动。总之，优雅的架构VicK与信号转导和传感器域建议的模型，其中DHp螺旋弯曲和CA摆动运动可能协调自激酶激活。双组分信号转导系统（TCSs）是新抗菌剂研究的有前途的目标，因为它们有助于细菌和真菌适应和生存。TCS的主要成分之一是传感器组氨酸激酶（SK），其将细胞外信号传递到细胞内途径。尽管进行了深入的研究，但SK的全长结构尚未得到解决。在这项研究中，我们报告的第一个晶体结构的完整的细胞质区的VicK，一个重要的SK在蛀牙病原体S。变种人VicK除了一个短的跨膜结构域外，还由几个结构域（HAMP、PAS、DHp以及催化和ATP结合结构域[CA]）组成。我们发现二聚体VicK蛋白具有优雅的棒状结构，其结构域线性连接，就像串上的珠子。该结构表明VicK激酶通过DHp结构域的螺旋弯曲和催化CA结构域周围的协调摆动与靶组氨酸接合来激活自身。基于结构的诱变实验也帮助我们确定了VicK相反的磷酸酶活性所需的关键残基。我们的多模块VicK蛋白的研究表明，顺序激酶激活模型，可能涉及螺旋弯曲的DHp域和重新定位的CA域。
A crystal structure reveals an elegant mechanistic switch whereby helical bending and catalytic domain rotation allow self-activation of a histidine kinase during a bacterial stress response. Two-component systems (TCSs) are important for the adaptation and survival of bacteria and fungi under stress conditions. A TCS is often composed of a membrane-bound sensor histidine kinase (SK) and a response regulator (RR), which are relayed through sequential phosphorylation steps. However, the mechanism for how an SK is switched on in response to environmental stimuli remains obscure. Here, we report the crystal structure of a complete cytoplasmic portion of an SK, VicK from Streptococcus mutans. The overall structure of VicK is a long-rod dimer that anchors four connected domains: HAMP, Per-ARNT-SIM (PAS), DHp, and catalytic and ATP binding domain (CA). The HAMP, a signal transducer, and the PAS domain, major sensor, adopt canonical folds with dyad symmetry. In contrast, the dimer of the DHp and CA domains is asymmetric because of different helical bends in the DHp domain and spatial positions of the CA domains. Moreover, a conserved proline, which is adjacent to the phosphoryl acceptor histidine, contributes to helical bending, which is essential for the autokinase and phosphatase activities. Together, the elegant architecture of VicK with a signal transducer and sensor domain suggests a model where DHp helical bending and a CA swing movement are likely coordinated for autokinase activation. Two-component signal transduction systems (TCSs) are promising targets for new antimicrobial research because they help bacteria and fungi adapt and survive. One of the main components of TCSs is a sensor histidine kinase (SK), which relays extracellular signals to intracellular pathways. Despite intensive research, a full-length structure of an SK has yet to be solved. In this study, we report the first crystal structure of the complete cytoplasmic region of VicK, an important SK in the tooth decay pathogen S. mutans. VicK is composed of several domains (HAMP, PAS, DHp, and catalytic and ATP binding domain [CA]) in addition to a short transmembrane domain. We find that the dimeric VicK protein has an elegant rod-shaped structure with the domains linearly connected like beads on a string. The structure suggests that VicK kinase activates itself by helical bending of the DHp domain and coordinated swinging around of the catalytic CA domain to engage with the target histidine. Structure-based mutagenesis experiments also helped us to identify key residues that are required for VicK's opposing phosphatase activity. Our studies of the multi-modular VicK protein suggest a sequential kinase activation model that may involve helical bending of the DHp domain and repositioning of the CA domains.
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DOI：
10.1080/07391102.2000.10506570
发表时间：
2000-04-01
影响因子：
4.4
作者：
Bansal, M;Kumar, S;Velavan, R
通讯作者：
Velavan, R
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
3.6
作者：
Dubrac, Sarah;Bisicchia, Paola;Msadek, Tarek
通讯作者：
Msadek, Tarek
影响因子：
2.1
作者：
Aravind, L;Ponting, CP
通讯作者：
Ponting, CP
DOI：
10.1107/s0907444998003254
发表时间：
1998-09-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Brunger, AT;Adams, PD;Warren, GL
通讯作者：
Warren, GL