A novel opportunity to combat the global Phosphorus crisis: investigating structure function relationships of an atypical phosphatase in soil bacteria

人类正面临着全球粮食安全的多重威胁，其中之一就是全球磷肥施用不平衡所导致的全球磷危机。为了可持续和持续的生存，人类迫切需要提高植物和动物分别从土壤或饲料中获取磷的效率。磷以多种无机和有机形式存在。生物体通常需要磷以一种简单的无机形式存在。不幸的是，大多数磷是在有机池中发现的，需要一种叫做磷酸酶的酶来释放生物可利用的磷酸盐。我们最近在一组环境细菌中发现了一种高活性和功能独特的磷酸酶（PafA），其性能优于先前表征的来自不同酶家族的磷酸酶。与根际相关的PafA变体可能代表最活跃的磷酸酶，尽管看起来具有相同的催化残基。本项目将利用蛋白质生物化学、定点诱变和结构生物学研究PafA的结构-功能关系。该学生将把来自强johnsoniae黄杆菌的PafA作为模型，并将其与通过下一代测序确定的不同PafA根际变异进行比较。这项工作将在全球磷循环中描述一种关键的新酶，这为加强可持续农业提供了一个令人兴奋的解决方案。

Humanity is facing several threats to global food security, one of which is the emerging global phosphorus crisis that has resulted from the imbalance in global application of phosphate fertilisers. For a sustainable and continued existence, humanity urgently needs to improve the efficiency by which plants and animals acquire phosphorus from soils or feed, respectively. Phosphorus exists in many inorganic and organic forms. Organisms typically need phosphorus to be in a simple inorganic form phosphate. Unfortunately, most phosphorus is found in an organic pool and enzymes called phosphatases are required to release the bioavailable phosphate. We recently identified a highly active and functionally unique phosphatase (PafA) in a group of environmental bacteria that outperforms previously characterised phosphatases from different enzyme families. PafA variants associated with the rhizosphere may represent the most active phosphatases, despite appearing to possess identical catalytic residues.This project will investigate structure-function relationships in PafA using protein biochemistry, site-directed mutagenesis and structural biology. The student will characterise PafA from Flavobacterium johnsoniae as the model and compare this with distinct PafA rhizosphere variants identified through next-generation sequencing. This work will characterise a key new enzyme in global phosphorus cycling, which presents an exciting solution for enhancing sustainable agriculture.