About This Project

The enzyme rubisco catalyzes the first step of carbon assimilation in photosynthesis and limits plant growth under many growth conditions. The aim of our work is to understand sequence-structural constraints on rubisco with the long-term goal of developing superlative variants that can improve photosynthesis in plants.

Ask the Scientists

What is the context of this research?

The enzyme rubisco catalyzes the first step of carbon assimilation in photosynthesis. Despite the massive flux of CO2 passing through this active site over billions of years, extant rubisco has slow kinetics, is prone to off-target activity and limits plant photosynthesis under many growth conditions. The aim of our work is to understand sequence-structural constraints on rubisco with the long-term goal of developing superlative variants. To this end, we have developed an E. coli platform for high-throughput assay and have carried out the first deep mutational scan of rubisco (Prywes et al. bioRxiv 2023). Our data reveal that systematic manipulation of enzyme kinetic parameters may be possible. We propose two approaches for engineering novel Rubisco enzymes with enhanced properties.

What is the significance of this project?

Rubisco is the key enzyme of the carbon assimilation reactions in a plant and is known to limit photosynthesis. It is thus hypothesized that improvements to photosynthesis could dramatically increase crop yields. Prior engineering work on rubisco has been limited by the low throughput of assays. We believe that our assay, coupled with new machine learning tools, will enable a thorough and, possibly, productive search for superlative variants. If successful, these results would be of significant interest to the biochemical community but would have obvious application in crop plants.

What are the goals of the project?

The goal of our work is to undertake a rigorous evaluation of the sequence-function landscape available to the enzyme rubisco to speed up the process of biological carbon fixation. This will lead to new biochemical insights and, possibly, the construction of novel rubisco variants which would have utility in planta. In work beyond the scope of this grant, our lab is building plant synthetic biology tools for rubisco validation and, if successful here, we will test out winners in model plants to clarify questions of photosynthetic performance and yield.