Amino acid sequences in metal-binding proteins with chelating properties offer exciting applications in biotechnology and medical research. To enhance their application in bioremediation studies, we explicitly aimed to identify specific metal-binding chelating motifs in protein structures for two significant pollutants, such as mercury (Hg²⁺) and chromium Cr(V1). For this purpose, we have performed an extensive coordination chemistry approach by retrieving Hg²⁺ and Cr(V1) binding protein structures from the protein database and validated using the B-factor, a term defining uncertainty of the atoms and with occupancy to obtain the best binding motifs. Our analysis revealed that acidic amino acids like aspartic acid, glutamic acid, and basic amino acids such as cysteine and histidine are predominant in coordinating with these metals. The order of preference in Hg²⁺-bound structures is predicted to be Cys > His > Asp > Glu, and for Cr(V1) is His > Asp > Glu. Examination of the atomic coordinates and their distance from each metal revealed that the sulfur atoms of cysteine showing more preference towards Hg²⁺coordination with an atomic distance ranging from 1.5 to 2.9 Å. Likewise, oxygen atoms of aspartic acid, glutamic acid and nitrogen atoms of histidine are within 2 Å of Cr(V1) coordination. Based on these observations, we obtained C–C–C, C-X(2)-C–C-(X)2-C, H–C–H motifs for Hg²⁺, and D-X(1)-D, H-X(3)-E motif for Cr(V1) to be shared within the coordination space of 3 Å. As a future scope, we propose that the identified metal-binding chelating motifs are oligopeptides and can display on the surface of microorganisms such as Escherichia coli and Saccharomyces cerevisiae for effective removal of natural Hg²⁺ and Cr(V1) through biosorption. Hence, our results will provide the basis for futuristic bioremediation.

具有螯合特性的金属结合蛋白中的氨基酸序列在生物技术和医学研究中提供了令人兴奋的应用。为了增强它们在生物修复研究中的应用，我们明确旨在为两种重要污染物（如汞( Hg ²⁺ )和铬 Cr(V1)）鉴定蛋白质结构中的特定金属结合螯合基序。为此，我们通过检索 Hg ^{2+进行了广泛的配位化学方法}和 Cr(V1) 结合蛋白结构来自蛋白质数据库，并使用 B 因子进行验证，该术语定义原子的不确定性并具有占用以获得最佳结合基序。我们的分析表明，天冬氨酸、谷氨酸等酸性氨基酸和半胱氨酸和组氨酸等碱性氨基酸在与这些金属的配位中占主导地位。^{Hg 2+}结合结构的优先顺序预计为 Cys > His > Asp > Glu，而 Cr(V1) 的优先顺序为 His > Asp > Glu。检查原子坐标及其与每种金属的距离表明，半胱氨酸的硫原子更倾向于 Hg ²⁺与原子距离范围为 1.5 至 2.9 Å 的配位。同样，天冬氨酸、谷氨酸的氧原子和组氨酸的氮原子在 Cr(V1) 配位的 2 Å 范围内。基于这些观察，我们获得了 Hg ²⁺和 DX(1)-D、HX( 3) Cr(V1) 的-E 基序在 3 Å 的配位空间内共享。作为未来的研究范围，我们建议鉴定的金属结合螯合基序是寡肽，可以展示在大肠杆菌和酿酒酵母等微生物的表面，通过生物吸附有效去除天然 Hg ²⁺和 Cr(V1)。因此，我们的结果将为未来的生物修复提供基础。