The dependency of red Rubisco on its cognate activase for enhancing plant photosynthesis and growth
Laura H. Gunn, Elena Martin Avila, Rosemary Birch, Spencer M. Whitney
Abstract
Significance The specialized assembly requirements of Rubisco hamper its bioengineering in plants, especially in regard to transforming in “red” Rubiscos from algae with better CO 2 -fixing properties that could enhance crop photosynthesis and growth. We show this assembly incompatibility does not extend to the “red” type Rubisco from Rhodobacter sphaeroides . Despite evolving from a different phylogenetic lineage to plant Rubisco, the assembly requirements of Rs Rubisco are readily met in chloroplasts as well as Escherichia coli . Coexpressing its cognate Rubisco activase enhanced Rs Rubisco activity and improved plant photosynthesis and growth twofold. Rs Rubisco provides a protein scaffold for red Rubisco bioengineering in E. coli and plants—requiring future optimisation of chloroplast Rs Rubisco expression and catalytic repair.