Characteristics of the First Protein Tyrosine Phosphatase with Phytase Activity from a Soil Metagenome.

Genis Andrés Castillo Villamizar,Rolf Daniel,Laura Griese,Heiko Nacke,Katrina Funkner,Lydia Tabernero

doi:10.3390/genes10020101

Genis Andrés Castillo Villamizar, Rolf Daniel + Show 4 more

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https://doi.org/10.3390/genes10020101

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Journal: Genes	Publication Date: Jan 29, 2019
Citations: 10	License type: CC BY 4.0

Affiliation: University of Göttingen, University of Manchester

Abstract

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 (pho16B), 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 (Km 0.966 mM). Pho16B contains the HCXXGKDR[TA]G submotif of PTP-ALPs, and it is structurally related to PtpB of Mycobacterium tuberculosis. This study demonstrates the presence and functionality of an environmental gene codifying a PTP-phytase homologous to enzymes closely associated to bacterial pathogenicity.

Highlights

Since the emergence of generation sequencing and omics approaches, the genetic material of numerous organisms, including bacterial, plant, and animal pathogens, has been analyzed
Function-based screening of a forest soil metagenomic library for genes coding for phosphatases and phytases yielded a positive Escherichia coli clone carrying the recombinant plasmid pLP16
All previously described and characterized Protein tyrosine phosphatases (PTPs) were derived from individual microorganisms

Summary

Introduction

Since the emergence of generation sequencing and omics approaches, the genetic material of numerous organisms, including bacterial, plant, and animal pathogens, has been analyzed. Genome analysis of single organisms, together with metagenomic and metaproteomic surveys comprising diverse environmental samples, provided an improved understanding of microbial biodiversity and the relationship of diversity with ecological, biotechnological, evolutionary or pathogenic processes [1,2,3]. Protein tyrosine phosphatases (PTPs) are an example of enzymes associated with virulence whose environmental homologues have not fully been studied. PTPs have multiple roles in cell metabolism. For many PTPs, their physiological substrate has not been identified [4].

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