Molecular 'Swiss Army knife' to make biofuel from algae

Researchers have built a molecular 'Swiss Army knife' that makes biofuels and other green chemical production from algae more viable.
Researchers fabricated a synthetic protein that not only improves the assembly of the carbon-fixing factory of cyanobacteria, also known as blue-green algae, but also provides a proof of concept for a device that could potentially improve plant photosynthesis or be used to install new metabolic pathways in bacteria.
"The multifunctional protein we've built can be compared to a Swiss Army knife," said lead author Raul Gonzalez-Esquer, doctoral researcher at the Michigan State University in US.
"From known, existing parts, we've built a new protein that does several essential functions," Gonzalez-Esquer said.

For the research, Gonzalez-Esquer worked with Cheryl Kerfeld, Professor of Structural Bioengineering in the Michigan State University-DOE Plant Research Lab, and Tyler Shubitowski, MSU undergraduate student.
Kerfield's lab studies bacterial microcompartments, or BMCs. These are self-assembling cellular organs that perform myriad metabolic functions, and are like molecular factories with many different pieces of machinery.

They modernised the factory by updating the carboxysome, a particularly complex BMC that requires a series of protein-protein interactions involving at least six gene products to form a metabolic core that takes carbon dioxide out of the atmosphere and converts it into sugar.
To streamline this process, the team created a hybrid protein in cyanobacteria, organisms that have many potential uses for making green chemicals or biofuels.

The new protein replaces four gene products, yet still supports photosynthesis. Reducing the number of genes needed to build carboxysomes should facilitate the transfer of carboxysomes into plants.
This installation should help plants' ability to fix carbon dioxide.
Improving their capacity to remove carbon dioxide from the atmosphere makes it a win-win, Gonzalez-Esquer said.
This proof of concept also shows that BMCs can be broken down to the sum of their parts, ones that can be exchanged.
Since they are responsible for many diverse metabolic functions, BMCs have enormous potential for bioengineering, said Kerfeld.
"We can now potentially redesign other naturally occurring factories or dream up new ones for metabolic processes we'd like to install in bacteria," she said.

The study was published in the journal Plant Cell.