Athens, Ga. – University of Georgia researchers have discovered that two proteins come together in an unexpected way to make a carbohydrate, a chain of sugar molecules, in plant cell walls. This fundamental discovery changes the way scientists think about how plant cell walls are made and opens a new door to converting plants to biofuels and other carbon-based products.
In 2006, the UGA research team, led by Debra Mohnen, a faculty member in the UGA Complex Carbohydrate Research Center, discovered GAUT1, the first protein shown to synthesize pectin, a major component of the plant cell wall. Now Mohnen's team has shown that GAUT1 and a genetically similar protein called GAUT7, which does not appear to have pectin-synthesizing activity by itself, form a critical part of a pectin-synthesizing protein complex.
Moreover, the two-protein complex may serve as a "core" complex that associates with additional pectin-synthesizing proteins to form still larger carbohydrate-synthesizing complexes in the plant cells.
The findings signify a "critical step in changing our view of how the plant cell wall is made," said principal investigator Mohnen, a professor of biochemistry and molecular biology in the UGA Franklin College of Arts and Sciences. The study was published this week in the Proceedings of the National Academy of Sciences.
