Visualising how plants make Rubisco

Increasing the photosynthetic capacity of crops is a promising strategy to meet the urgent global demand for increased food production. Central to various efforts to increase crop yield through improved photosynthetic capacity is the carbon-fixing enzyme Rubisco. Given its importance, surprisingly little is known about the molecular mechanisms of gene expression that support production of Rubisco and thereby maintain photosynthetic activity. In this project, we will investigate how translation in the chloroplast allow plants to produce Rubisco. We will also explore the question of how Rubisco expression is selectively activated or repressed in different cell types of C4 plants.

This exciting project will employ a variety of cutting-edge methods. Cryogenic electron microscopy (cryo-EM) will be employed to visualise the structure of gene expression complexes. Biophysical methods, such as surface plasmon resonance (SPR), will be used to measure molecular interactions of proteins with other proteins and with RNA. Proteomic methods and biochemical assays will be employed. These discoveries will support the long-term effort to better control photosynthetic output and timing for improved crops and biotechnologies. They will also shed new light on fundamental biological questions of how genes are read, and the evolutionary relationship between chloroplasts and bacteria.

The student will be trained in diverse and transferrable scientific skills. Special attention will be given to training in cryo-EM, a speciality of our team that represents an increasingly powerful method of visualising large and dynamic molecular machines. National and international conference attendance is expected. The JIC hosts a wealth of expertise in plant biology, gene expression mechanisms, and structural biology, and is therefore an excellent research environment for this project.

References

Structure of the plant plastid-encoded RNA polymerase. Vergara-Cruces A, Pramanick I, Pearce D, Vogirala VK, Byrne MJ, Low JKK and Webster MW (2024). Cell 187:1145-1159. PMID: 38428394

Structural basis of transcription-translation coupling and collision in bacteria. Webster MW, Takacs M, Zhu C, Vidmar V, Eduljee A, Abdelkareem M, Weixlbaumer A (2020) Science 369:1355-59. PMID: 32820062

Molecular basis of mRNA delivery to the bacterial ribosome. Webster MW, Chauvier A, Rahil H, Graziadei A, Charles K, Takacs M, Saint-André C, Rappsilber J, Walter, NG, Weixlbaumer A (2024). BioRxiv. DOI: 10.1101/2024.03.19.585789

RNA-binding proteins distinguish between similar sequence motifs to promote targeted deadenylation by Ccr4-Not. Webster MW, Stowell JAW, Passmore LA (2019) eLife 8:e40670. PMID: 30601114

mRNA deadenylation is coupled to translation rates by the differential activities of Ccr4-Not nucleases. Webster MW, Chen YH, Stowell JAW, Alhusaini N, Graveley B, Coller J, Passmore LA (2018) Molecular Cell, 70(6): 1089-1100. PMID: 29932902