Harnessing the Catalytic Potential of Nitrogenases

Introduction

Biological nitrogen fixation is nature’s alternative to the industrial Haber-Bosch process that currently feeds at least half of the human world population through the provision of nitrogen fertilizers. In addition to its high energy demand, the process increasingly leads to various ecological problems, as its annual output steadily grows with demand.

Environmental Impact

Haber-Bosch ammonia synthesis leads to the release of the greenhouse gases CO2 and N2O and to eutrophication of waters and aquifers because a substantial portion of nitrogen is lost to competing chemical and biological processes. One solution for this is to transfer the enzyme directly into food crops.

Project Overview

GOFIXIT will establish the recombinant production of a complete nitrogenase enzyme system in a heterologous host and make a link to central metabolism, effectively converting the host into a functional diazotroph.

Nitrogenase Characteristics

Nitrogenase is a two-component metalloenzyme that is uniquely able to reduce chemically inert, atmospheric N2 into its bioavailable form, ammonium. It occurs only in prokaryotes, is highly sensitive to O2, and it requires large amounts of metabolic energy in the form of ATP and a strong reductant for catalysis.

Research Approach

To obtain a functional production system, all these points must be addressed in parallel. Based on our long record of research on nitrogenases, we are ideally positioned to succeed, focusing on our unique competence in preparative protein biochemistry and analysis.

Achievements

We have produced, isolated, and structurally characterized all three nitrogenase isoforms and developed the spectroscopic and structural tools for a detailed analysis of their intricate metal cofactors.

Focus Areas

GOFIXIT focuses on the production of the enzyme components, and based on their analysis, chooses, tunes, and applies the required accessory machineries for the synthesis, maturation, transfer, and insertion of the catalytic metal centers that are unique to this class of enzymes.