Close proximity of phosphorylation sites to ligand in the phosphoproteome of the extreme thermophile Thermus thermophilus HB8
Close proximity of phosphorylation sites to ligand in the phosphoproteome of the extreme thermophile Thermus thermophilus HB8
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极端嗜热菌 HB8 磷酸化蛋白质组中的磷酸化位点与配体非常接近
DOI：
10.1002/pmic.201100573
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发表时间：
2012
期刊：
影响因子：
3.4
通讯作者：
Yoshio Takahata
中科院分区：
文献类型：
--
作者：
Uchida Y;Shimomura T;Hirayama J;Nishina H.;清水重臣;Yoshio Takahata
我们使用无凝胶质谱方法对来自极度嗜热革兰氏阴性真细菌嗜热栖热菌HB8的蛋白质进行了磷酸蛋白质组分析。我们从 48 种蛋白质中鉴定出 52 种磷酸肽，并确定了 46 个磷酸化位点：30 个位于丝氨酸、12 个位于苏氨酸、4 个位于酪氨酸。已知已鉴定的磷蛋白参与多种细胞过程。为了帮助阐明这些磷酸化事件的功能作用，我们将磷酸化位点绘制在各个蛋白质的已知三级结构上。总之，我们成功地将 46 个位点（约 88%）绘制到相应的结构上。发现大多数磷酸化位点位于二级结构的环和末端区域。令人惊讶的是，其中 28 个位点位于酶的活性位点处或附近。特别是，18 个位点位于配体 4 Å 范围内，包括底物或辅因子。这种结构位置表明磷酸化除了诱导构象变化之外还对配体结合产生直接影响。有趣的是，这 28 个磷酸化位点中有 19 个位于底物或辅因子的磷酸部分附近。在寡聚蛋白中，在亚基界面处发现了 5 个磷酸化位点。基于这些结果，我们提出了一种涉及 T 中 Ser/Thr/Tyr 磷酸化的调节机制。嗜热菌HB8。
We performed phosphoproteome analysis of proteins from the extremely thermophilic Gram‐negative eubacteriumThermus thermophilusHB8 using gel‐free mass spectrometric method. We identified 52 phosphopeptides from 48 proteins and determined 46 phosphorylation sites: 30 on serine, 12 on threonine, and 4 on tyrosine. The identified phosphoproteins are known to be involved in a wide variety of cellular processes. To help elucidate the functional roles of these phosphorylation events, we mapped the phosphorylation sites on the known tertiary structures of the respective proteins. In all, we succeeded in mapping 46 sites (approximately 88%) on the corresponding structures. Most of the phosphorylation sites were found to be located on loops and terminal regions of the secondary structures. Surprisingly, 28 of these sites were situated at or near the active site of the enzyme. In particular, 18 sites were within 4 Å of the ligand, including substrate or cofactor. Such structural locations suggest direct effects of the phosphorylation on the binding of ligand in addition to inducing a conformational change. Interestingly, 19 of these 28 phosphorylation sites were situated near the phosphate moiety of a substrate or cofactor. In oligomeric proteins, 5 phosphorylation sites were found at the subunit interface. Based on these results, we propose a regulatory mechanism that involves Ser/Thr/Tyr phosphorylation inT. thermophilusHB8.