New research on an enzyme that is essential for photosynthesis and all life on earth has uncovered a key finding in its structure which reveals how light can interact with matter to make an essential pigment for life.

The work gives a structural understanding of how a light activated enzyme involved in chlorophyll synthesis works. Light activated enzymes are rare in nature, with only three known. This enzyme in particular, called protochlorophyllide oxidoreductase or ‘POR’, is responsible for making the pigment vital for chlorophyll in plants. Without chlorophyll, there is no photosynthesis and no plant life.

Understanding the structure of the POR enzyme gives a rare glimpse of how a natural light-activated enzyme works. Chemists and bio-scientists alike have been fascinated by light activation of biological catalysis for many years and understanding how light can drive enzyme reactions has been a major challenge.

The revealed structure shows how the architecture of the enzyme allows one of the reactants to capture light and channel it to drive a crucial biological reaction involved in chlorophyll synthesis. Understanding these fundamental concepts should have major implications for the design of new light-activated chemical and biochemical catalysts which are increasingly important in the use of enzymes in chemical manufacture.