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Title: Small subunits can determine enzyme kinetics of tobacco Rubisco expressed in Escherichia coli
Rubisco catalyses the first step in carbon fixation and is a strategic target to improve photosynthetic efficiency. In plants, Rubisco is composed of eight large and eight small subunits and its biogenesis requires multiple chaperones. We optimised a system to produce tobacco Rubisco in Escherichia coli by co-expressing chaperones in auto-induction medium. We successfully assembled tobacco Rubisco in E. coli with each small subunit that is normally encoded by the nuclear genome. Even though each enzyme carries only a single type of small subunit in E. coli, the enzymes exhibit carboxylation kinetics very similar to that of the native Rubisco. Tobacco Rubisco assembled with a recently discovered trichome small subunit has a higher catalytic rate and a lower CO2 affinity than those assembled with other small subunits. Our E. coli expression system will allow probing of features of both subunits of Rubisco that affect its kinetic properties.  more » « less
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Nature Plants
Medium: X
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National Science Foundation
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