Structural basis for the regulation mechanism of the tyrosine kinase CapB from Staphylococcus aureus.
Structural basis for the regulation mechanism of the tyrosine kinase CapB from Staphylococcus aureus.
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DOI：
10.1371/journal.pbio.0060143
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发表时间：
2008-06-10
期刊：
影响因子：
9.8
通讯作者：
Nessler S
中科院分区：
文献类型：
--
作者：
Olivares-Illana V;Meyer P;Bechet E;Gueguen-Chaignon V;Soulat D;Lazereg-Riquier S;Mijakovic I;Deutscher J;Cozzone AJ;Laprévote O;Morera S;Grangeasse C;Nessler S
人们认为细菌缺乏酪氨酸磷酸化酶。然而，最近在细菌中发现了几种与其真核对应物相似的酪氨酸激酶。它们参与许多生理过程，但由于其结构表征进展缓慢，人们对它们的准确功能仍然知之甚少。它们的最佳特征是参与细胞外多糖合成和输出的共聚酶。这些化合物在病原菌的毒力中发挥着关键作用，因此细菌酪氨酸激酶可以被视为潜在的治疗靶点。在这里，我们展示了来自人类病原体金黄色葡萄球菌的酪氨酸激酶 CapB 的磷酸化和非磷酸化状态的晶体结构及其同源跨膜调节剂 CapA 的激活剂结构域。细菌酪氨酸激酶的第一个高分辨率结构揭示了一个 230 kDa 的环形八聚体，该八聚体在分子间自磷酸化时解离。这些观察结果为细菌酪氨酸激酶的调节机制提供了分子基础，并深入了解了它们的共聚酶功能。一类特殊的新型细菌酶，即细菌酪氨酸激酶（BY-激酶）已得到表征。这些酶参与越来越多的生理过程，从应激抵抗到致病性，与真核激酶没有序列相似性，并且它们的功能仍然很大程度上未知。然而，它们被描述为在 C 末端酪氨酸簇上进行自磷酸化并磷酸化内源蛋白质底物。我们在这里描述了细菌酪氨酸激酶的第一个晶体结构，即来自病原体金黄色葡萄球菌的 CapB，与跨膜刺激蛋白 CapA 的细胞质结构域复合。我们的数据解释了 CapA 激活 CapB 的机制，并使我们能够提出基于分子间自磷酸化的调节机制。这些结果还为内源底物 CapO（一种参与多糖前体合成的酶）的磷酸化提供了新的见解。 CapA 和 CapB 等作为共聚酶参与胞外多糖的合成，胞外多糖被认为是有效的毒力因子。因此，这些结构数据为设计这些酶的特异性抑制剂提供了基础，这构成了开发治疗传染病新药的原始且有吸引力的靶标。对金黄色葡萄球菌保守的细菌酪氨酸激酶的结构分析为破译其调节机制提供了基础，从而建立了其在细胞外多糖合成中的影响模型。
Bacteria were thought to be devoid of tyrosine-phosphorylating enzymes. However, several tyrosine kinases without similarity to their eukaryotic counterparts have recently been identified in bacteria. They are involved in many physiological processes, but their accurate functions remain poorly understood due to slow progress in their structural characterization. They have been best characterized as copolymerases involved in the synthesis and export of extracellular polysaccharides. These compounds play critical roles in the virulence of pathogenic bacteria, and bacterial tyrosine kinases can thus be considered as potential therapeutic targets. Here, we present the crystal structures of the phosphorylated and unphosphorylated states of the tyrosine kinase CapB from the human pathogen Staphylococcus aureus together with the activator domain of its cognate transmembrane modulator CapA. This first high-resolution structure of a bacterial tyrosine kinase reveals a 230-kDa ring-shaped octamer that dissociates upon intermolecular autophosphorylation. These observations provide a molecular basis for the regulation mechanism of the bacterial tyrosine kinases and give insights into their copolymerase function. An idiosyncratic new class of bacterial enzymes, bacterial tyrosine-kinases (BY-kinases), has been characterized. These enzymes, which are involved in an increasing number of physiological processes ranging from stress resistance to pathogenicity, share no sequence similarities with eukaryotic kinases, and their function remains largely unknown. They have nevertheless been described to undergo autophosphorylation on a C-terminal tyrosine cluster and to phosphorylate endogenous protein substrates. We describe here the first crystal structure of a bacterial tyrosine kinase, namely CapB from the pathogen Staphylococcus aureus, in complex with the cytoplasmic domain of the transmembrane stimulatory protein CapA. Our data explain the activation mechanism of CapB by CapA and allow us to propose a regulatory mechanism based on intermolecular autophosphorylation. These results also give new insights onto the phosphorylation of the endogenous substrate CapO, an enzyme involved in the synthesis of polysaccharide precursors. CapA and CapB, among others, are involved as copolymerases in the synthesis of extracellular polysaccharides that are thought to be potent virulence factors. Thus, these structural data provide the basis for designing specific inhibitors for these enzymes, which constitute an original and attractive target for the development of new drugs to treat infectious diseases. Structural analysis of a conserved bacterial tyrosine kinase fromStaphylococcus aureus provides the basis for deciphering its regulatory mechanism, leading to a model for its implication in extracellular polysaccharide synthesis.
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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
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
DOI：
10.1073/pnas.192368699
发表时间：
2002-10-15
影响因子：
11.1
作者：
Fieulaine, S;Morera, S;Nessler, S
通讯作者：
Nessler, S
影响因子：
4.8
作者：
Grangeasse, C;Obadia, B;Doublet, P
通讯作者：
Doublet, P
影响因子：
3.2
作者：
Bender, MH;Cartee, RT;Yother, J
通讯作者：
Yother, J