Plants release oxygen by absorbing carbon dioxide and breaking down water
using sunlight through photosynthesis. However, little is known about the
mechanics of how plants create oxygen during photosynthesis. Scientists at
Louisiana State University (LSU) studied the cellular system responsible for
creating oxygen during photosynthesis called Photosystem II. They analyzed
two proteins that are critical to creating oxygen, and how they connect and
interact.

Manjula Mummadisetti, a graduate student at LSU's Department of Biological
Sciences, created a 3D model of the two critical proteins, PsbP and PsbQ, to
see how they function. She isolated the chloroplasts from spinach, and
treated them with a chemical detergent to extract a high concentration of
Photosystem II. She then used high-resolution mass spectrometry to see where
the two proteins overlap and connect.

According to LSU Professor Terry Bricker, the two proteins are like parts of
a car that enable oil to reach the engine. In plants, the "oil" is calcium
and chloride and the "fuel" is water and sunlight. The structure of PsbP and
PsbQ facilitates the efficient use of calcium and chloride in a plant,
enabling it to produce oxygen.


[www.lsu.edu]
[www.lsu.edu]