Distinct single amino acid replacements in the control of virulence regulator protein differentially impact streptococcal pathogenesis.
Distinct single amino acid replacements in the control of virulence regulator protein differentially impact streptococcal pathogenesis.
复制标题
DOI：
10.1371/journal.ppat.1002311
复制
发表时间：
2011-10
期刊：
影响因子：
6.7
通讯作者：
Shelburne SA 3rd
中科院分区：
文献类型：
--
作者：
Horstmann N;Sahasrabhojane P;Suber B;Kumaraswami M;Olsen RJ;Flores A;Musser JM;Brennan RG;Shelburne SA 3rd
对 A 族链球菌 (GAS) 入侵菌株的测序揭示了编码毒力调节蛋白 (CovR) 蛋白控制的基因中存在多种单核苷酸多态性。然而，关于 CovR 单氨基酸替代影响 GAS 发病机制的分子机制的信息有限。 CovR C 端 DNA 结合结构域的晶体结构被确定为 1.50 Å 分辨率，并显示出三链 β 折叠，随后是翼状螺旋-转角-螺旋 DNA 结合基序。 CovR 蛋白质-DNA 复合物的建模表明，在临床 GAS 分离株中观察到的 CovR 单氨基酸替代可以直接改变蛋白质-DNA 相互作用并影响蛋白质结构。与野生型相比，通过 CovR DNA 结合域中的单个氨基酸替换而变化的同等位基因 GAS 菌株具有显着不同的转录组。类似地，不同的重组CovR变体对来自几个毒力因子编码基因的启动子区域的DNA具有不同的结合亲和力。最后，接受 GAS CovR 同等位基因菌株攻击的小鼠的存活时间显着不同，这与转录组和蛋白质-DNA 结合研究相关。总而言之，这些数据为 CovR 蛋白变异对 GAS 发病机制的关键和独特影响提供了结构和功能见解。 A 组链球菌 (GAS) 会引起多种人类感染，包括通常致命的侵袭性疾病。引起严重感染的 GAS 菌株可能毒力调节蛋白 (CovR) 控制蛋白的氨基酸序列发生改变，但 CovR 蛋白的变化影响 GAS 疾病的机制尚不清楚。我们确定了 CovR DNA 结合区域的晶体结构，并发现在临床、侵袭性 GAS 分离株中观察到的 CovR 蛋白的改变可能会破坏 CovR-DNA 相互作用和整体 CovR 结构。根据结构数据，具有单个氨基酸变化的CovR蛋白对各种GAS毒力因子编码基因具有明显不同的结合亲和力。同样，仅存在单个 CovR 氨基酸变化的 GAS 菌株具有不同的基因表达谱。最后，用仅单个 CovR 氨基酸替换不同的 GAS 菌株攻击的小鼠具有显着不同的生存时间，这与 CovR 蛋白的改变是 GAS 人类感染临床结果的关键决定因素的观点一致。这些发现为微妙的遗传差异如何深刻影响细菌感染的严重程度提供了机制见解。
Sequencing of invasive strains of group A streptococci (GAS) has revealed a diverse array of single nucleotide polymorphisms in the gene encoding the control of virulence regulator (CovR) protein. However, there is limited information regarding the molecular mechanisms by which CovR single amino acid replacements impact GAS pathogenesis. The crystal structure of the CovR C-terminal DNA-binding domain was determined to 1.50 Å resolution and revealed a three-stranded β-sheet followed by a winged helix-turn-helix DNA binding motif. Modeling of the CovR protein-DNA complex indicated that CovR single amino acid replacements observed in clinical GAS isolates could directly alter protein-DNA interaction and impact protein structure. Isoallelic GAS strains that varied by a single amino acid replacement in the CovR DNA binding domain had significantly different transcriptomes compared to wild-type and to each other. Similarly, distinct recombinant CovR variants had differential binding affinity for DNA from the promoter regions of several virulence factor-encoding genes. Finally, mice that were challenged with GAS CovR isoallelic strains had significantly different survival times, which correlated with the transcriptome and protein-DNA binding studies. Taken together, these data provide structural and functional insights into the critical and distinct effects of variation in the CovR protein on GAS pathogenesis. Group A Streptococcus (GAS) causes a variety of human infections including invasive disease that can often be deadly. GAS strains that cause serious infections may have alterations in the amino acid sequence of the control of virulence regulator (CovR) protein, but mechanisms by which changes in the CovR protein influence GAS disease are not understood. We determined the crystal structure of the CovR DNA binding region and found that alterations in the CovR protein observed in clinical, invasive GAS isolates are likely to disrupt CovR-DNA interaction and overall CovR structure. In accord with the structural data, CovR proteins with a single amino acid change had distinctly different binding affinities for various GAS virulence-factor encoding genes. Similarly, GAS strains that differed by only the presence of a single CovR amino acid change had distinct gene expression profiles. Finally, mice that were challenged with GAS strains that differed by only a single CovR amino acid replacement had significantly different survival times consistent with the idea that alterations in the CovR protein are a key determinant of clinical outcomes in GAS human infections. These findings provide mechanistic insights into how subtle genetic differences can profoundly impact the severity of bacterial infections.
登录
查看更多内容
影响因子：
6.4
作者：
Hoe, NP;Vuopio-Varkila, J;Musser, JM
通讯作者：
Musser, JM
M1T1 A 组链球菌菌毛促进上皮定植，但通过中性粒细胞胞外截留降低全身毒力。
影响因子：
4.7
作者：
Alexander, Laura E. Crotty;Maisey, Heather C.;Timmer, Anjuli M.;Rooijakkers, Suzan H. M.;Gallo, Richard L.;von Koeckritz-Blickwede, Maren;Nizet, Victor
通讯作者：
Nizet, Victor
DOI：
10.1073/pnas.0803815105
发表时间：
2008-10-28
影响因子：
11.1
作者：
Gryllos, Ioannis;Tran-Winkler, Hien J.;Wessels, Michael R.
通讯作者：
Wessels, Michael R.
影响因子：
3.7
作者：
Beres SB;Musser JM
通讯作者：
Musser JM
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