Probing function and structure of trehalose-6phosphate phosphatases from pathogenic organisms suggests distigroupingsnct molecular
Probing function and structure of trehalose-6phosphate phosphatases from pathogenic organisms suggests distigroupingsnct molecular
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DOI：
10.1096/fj.201601149r
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发表时间：
2017-03-01
期刊：
影响因子：
4.8
通讯作者：
Hofmann, Andreas
中科院分区：
文献类型：
--
作者：
Cross, Megan;Lepage, Romain;Hofmann, Andreas
海藻糖生物合成途径对于开发新的治疗剂具有极大的意义，因为海藻糖是许多病原体中必需的二糖，但在哺乳动物宿主中既不需要也不合成。因此，海藻糖-6-磷酸磷酸酶（TPP），海藻糖生物合成的关键酶，可能是一个有吸引力的新的化疗药物的目标。基于对寄生线虫和细菌的基因组的调查，并通过基于结构的氨基酸序列比对，我们推导出单酶TPPs的拓扑结构，并将其分为3组。位于TPPs的活性位点的氨基酸残基的功能作用的比较属于不同的群体揭示了细微的变化。由于目前的文献对这个酶家族的倾向，推断单个氨基酸残基的功能作用，我们调查的作用，严格保守的天冬氨酸四分体的TPP的线虫马来丝虫通过使用保守的突变方法。与推测对底物进行亲核攻击的残基天冬氨酸-213相反，我们发现BmTPP的天冬氨酸-215和天冬氨酸-428参与底物的酶促水解的化学步骤。因此，我们建议通过单酶TPP的序列比较对功能重要的氨基酸进行基于同源性的推断应仅对3组中的每一组进行。克罗斯，M.，Lepage，R.，Rajan，S.，Biberacher，S.，北卡罗来纳州扬，金，B.- N.，Coster，M.J.，Gasser，R.B.，金，J. -美国，Hofmann，A.从病原生物体中探测海藻糖-6-磷酸磷酸酶的功能和结构表明不同的分子分组。
The trehalose biosynthetic pathway is of great interest for the development of novel therapeutics because trehalose is an essential disaccharide in many pathogens but is neither required nor synthesized in mammalian hosts. As such, trehalose-6-phosphate phosphatase (TPP), a key enzyme in trehalose biosynthesis, is likely an attractive target for novel chemotherapeutics. Based on a survey of genomes from a panel of parasitic nematodes and bacterial organisms and by way of a structure-based amino acid sequence alignment, we derive the topological structure of monoenzyme TPPs and classify them into 3 groups. Comparison of the functional roles of amino acid residues located in the active site for TPPs belonging to different groups reveal nuanced variations. Because current literature on this enzyme family shows a tendency to infer functional roles for individual amino acid residues, we investigated the roles of the strictly conserved aspartate tetrad in TPPs of the nematode Brugia malayi by using a conservative mutation approach. In contrast to aspartate-213, the residue inferred to carry out the nucleophilic attack on the substrate, we found that aspartate-215 and aspartate-428 of BmTPP are involved in the chemistry steps of enzymatic hydrolysis of the substrate. Therefore, we suggest that homology-based inference of functionally important amino acids by sequence comparison for monoenzyme TPPs should only be carried out for each of the 3 groups.-Cross, M.,Lepage, R.,Rajan, S., Biberacher, S.,Young, N.D.,Kim, B.-N., Coster, M.J., Gasser, R.B., Kim, J.-S., Hofmann, A. Probing function and structure of trehalose-6-phosphate phosphatases from pathogenic organisms suggests distinct molecular groupings.