Department of Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany.
Línea Tecnológica Biocorrosión, Corporación para la investigación de la corrosión C.I.C. Piedecuesta, Santander, Colombia.
Genes (Basel). 2019 Jan 29;10(2):101. doi: 10.3390/genes10020101.
Protein tyrosine phosphatases (PTPs) fulfil multiple key regulatory functions. Within the group of PTPs, the atypical lipid phosphatases (ALPs) are known for their role as virulence factors associated with human pathogens. Another group of PTPs, which is capable of using inositol-hexakisphosphate (InsP₆) as substrate, are known as phytases. Phytases play major roles in the environmental phosphorus cycle, biotechnology, and pathogenesis. So far, all functionally characterized PTPs, including ALPs and PTP-phytases, have been derived exclusively from isolated microorganisms. In this study, screening of a soil-derived metagenomic library resulted in identification of a gene (), encoding a PTP, which shares structural characteristics with the ALPs. In addition, the characterization of the gene product (Pho16B) revealed the capability of the protein to use InsP₆ as substrate, and the potential of soil as a source of phytases with so far unknown characteristics. Thus, Pho16B represents the first functional environmentally derived PTP-phytase. The enzyme has a molecular mass of 38 kDa. The enzyme is promiscuous, showing highest activity and affinity toward naphthyl phosphate (K 0.966 mM). Pho16B contains the HCXXGKDR[TA]G submotif of PTP-ALPs, and it is structurally related to PtpB of . This study demonstrates the presence and functionality of an environmental gene codifying a PTP-phytase homologous to enzymes closely associated to bacterial pathogenicity.
蛋白质酪氨酸磷酸酶（PTPs）发挥着多种关键的调节功能。在 PTPs 家族中，非典型脂质磷酸酶（ALPs）因其作为与人类病原体相关的毒力因子的作用而闻名。另一组 PTPs 能够使用肌醇六磷酸（InsP₆）作为底物，被称为植酸酶。植酸酶在环境磷循环、生物技术和发病机制中发挥着重要作用。到目前为止，所有具有功能特征的 PTPs，包括 ALPs 和 PTP-植酸酶，都是从分离的微生物中衍生出来的。在这项研究中，对土壤衍生的宏基因组文库进行筛选，鉴定出一个基因（），它编码一种 PTP，与 ALPs 具有结构特征。此外，对基因产物（Pho16B）的特性进行了研究，揭示了该蛋白能够利用 InsP₆作为底物，以及土壤作为具有未知特性的植酸酶来源的潜力。因此，Pho16B 代表了第一个功能性的环境衍生 PTP-植酸酶。该酶的分子量为 38 kDa。该酶具有混杂性，对萘基磷酸酯表现出最高的活性和亲和力（K 0.966 mM）。Pho16B 含有 PTP-ALPs 的 HCXXGKDR[TA]G 亚基序，与 中的 PtpB 结构上相关。本研究证明了一种环境基因的存在和功能，该基因编码一种与细菌致病性密切相关的 PTP-植酸酶同源物。
