Moonlighting enzyme works double shift 24/7

Jan 31, 2012
MSU researchers found a moonlighting enzyme in Arabidopsis that works double shifts 24/7. Credit: Photo illustration by G.L. Kohuth

A team of researchers led by Michigan State University has discovered an overachieving plant enzyme that works both the day and night shifts.

The discovery, featured in the current issue of , shows that plants evolved a new function for this enzyme by changing merely one of its protein building blocks.

The enzyme, , usually works the , serving as a key player in created through photosynthesis in the . When the sun goes down most of these enzymes switch off to prevent energy from leaking out.

The newly changed protein building block, or subunit, allows this enzyme to do another job once the sun goes down and photosynthesis stops, said David Kramer, Hannah Distinguished Professor of Photosynthesis and Bioenergetics.

"By exchanging this one building block, the enzyme gains a new function in the dark, in the roots." he said. "It's like a food processor. With one attachment it chops food. Swap it for another, and it kneads bread dough."

The building block on which the researchers focused is called gamma, a component of ATP synthase. There are two forms of gamma, gamma-1 and gamma-2. When researchers removed gamma-1, photosynthesis was completely stopped. When gamma-2 was removed, the plant could not make normal root hairs (the part of the root that takes up nutrients.) On the other end of the spectrum, plants engineered to produce lots of gamma-2 made very long .

So, the seemingly small change not only allows the enzyme to pick up an additional shift, but to also work a completely different job – from storing energy during the day to transporting energy in the roots at night.

This particular enzyme also functions as a regulator of photosynthesis, controlling how much energy plants consume. Too much light causes damage while too little results in low energy, which keeps the plants from growing to their full potential.

Kramer's next phase of research in this realm will investigate regulating the enzyme's effect on increasing photosynthesis, which could potentially lead to more efficient plants and algae.

Kramer works in the MSU-Department of Energy Plant Research Laboratory. The research team included scientists from Washington State University, Ludwig Maximilians University (Germany), Albert Ludwigs University (Germany) and the Centre de la Recherche Scientifique (France).

Explore further: How plant cell compartments change with cell growth

Related Stories

Researchers decipher the molecular basis of blue-green algae

Aug 01, 2011

Under normal conditions, cyanobacteria, also termed blue-green algae, build up energy reserves that allow them to survive under stress such as long periods of darkness. They do this by means of a molecular switch in an enzyme. ...

Study shows vitamin C is essential for plant growth

Sep 24, 2007

Scientists from the University of Exeter and Shimane University in Japan have proved for the first time that vitamin C is essential for plant growth. This discovery could have implications for agriculture and for the production ...

Recommended for you

How plant cell compartments change with cell growth

Aug 22, 2014

A research team led by Kiminori Toyooka from the RIKEN Center for Sustainable Resource Science has developed a sophisticated microscopy technique that for the first time captures the detailed movement of ...

Plants can 'switch off' virus DNA

Aug 22, 2014

A team of virologists and plant geneticists at Wageningen UR has demonstrated that when tomato plants contain Ty-1 resistance to the important Tomato yellow leaf curl virus (TYLCV), parts of the virus DNA ...

A better understanding of cell to cell communication

Aug 22, 2014

Researchers of the ISREC Institute at the School of Life Sciences, EPFL, have deciphered the mechanism whereby some microRNAs are retained in the cell while others are secreted and delivered to neighboring ...

A glimpse at the rings that make cell division possible

Aug 22, 2014

Forming like a blown smoke ring does, a "contractile ring" similar to a tiny muscle pinches yeast cells in two. The division of cells makes life possible, but the actual mechanics of this fundamental process ...

User comments : 0