Recent Posts

Condensation of Rubisco into a proto-pyrenoid in higher plant chloroplasts (bioRxiv)

Rubisco is a major enzyme in assimilating CO2 during photosynthesis. The efficiency of CO2 assimilation is compromised by a low ratio of CO2/O2, especially in C3 plants like rice, wheat and soybean. Algae sequester Rubisco as a condensate in a microcompartment called a pyrenoid within the chloroplast…

The dependency of red Rubisco on its cognate activase for enhancing plant photosynthesis and growth (Proc. Natl. Acad. Sci. USA)

The rate of carboxylation by Rubisco versus the rate of the competing oxygenation reaction limits photosynthesis in some conditions, so many researchers are investigating ways to enhance Rubisco. Rubisco is not limited to green plants but can be found in other lineages including red algae and photosynthetic…

Review: Biomolecular condensates in photosynthesis and metabolism ($) (Curr. Opin. Plant Biol.)

Biomolecular condensates are membraneless organelles with the capacity to spatially concentrate biomolecules. Liquid-liquid phase separation (LLPS) is one mechanism of condensate formation in which demixing of macromolecules leads to separation into dense and light phases. Photosynthetic organisms like…

Small subunits can determine enzyme kinetics of tobacco Rubisco expressed in Escherichia coli (Nature Plants)

Rubisco is the enzyme responsible for the fixation of CO2 to ribulose-1,5-bisphosphate (RuBP) during photosynthetic reactions. However, this enzyme has some functional issues, such as a slow catalytic turnover rate and sensitivity to temperature and CO2, and it catalyzes a competing oxygenation process…

Back to where it came from: chloroplast expression of both Rubisco subunits helps functional enzyme analysis

Rubisco catalyzes the key carboxylation step in photosynthetic CO2 fixation and is probably the most abundant protein on Earth. The enzyme is famous for inefficient catalysis and the habit of binding oxygen instead of CO2 in one out of every four binding events, leading to photorespiration reactions…

Stimulating photosynthetic processes increases productivity and water-use efficiency in the field (Nature Plants)

Yield potential in crops is determined by the efficiency of photosynthetic rates, which is a critical target for improvement. Previous studies have shown that photosynthetic carbon assimilation and plant biomass can be improved by the stimulation of either regeneration of RuBP (the five-carbon sugar…

Back to the Future for Plant Rubisco Bioengineering

Martin-Avila et al. use synthetic biology to improve photosynthesis in tobacco by swapping out the endogenous small subunits of Rubisco for one coming from potato, among other things. Plant Cell https://doi.org/10.1105/tpc.20.00288 By Spencer Whitney, Elena Martin-Avila, Sally Buck, Timothy Rhodes,…

Rubisco accumulation factor 1 and carboxysome biogenesis (PNAS)

Carbon concentration mechanisms (CCMs) refer to a diverse set of strategies by which photosynthetic organisms increase the amount of carbon dioxide available to the carbon-fixing enzyme Rubisco. The cyanobacterial CCM relies on the carboxysome, a membraneless microcompartment with a core of densely…

BSD2 is a Rubisco specific assembly chaperone, forms intermediary hetero‐oligomeric complexes and is non‐limiting to growth in tobacco (Plant Cell Environ)

The rubisco holoenzyme is comprised of eight large subunits and eight small subunits (L8S8).  Several auxiliary proteins are required to correctly assemble the functional protein. In this manuscript, Conlan et al investigate the chaperone function of one of these proteins, BSD2, in tobacco. The authors…