Conlan, BrendonBirch, RosemaryKelso, CelineHarrison, JulianOakley, AaronBeck, JennyWhitney, Spencer2017-12-142017-12-147/12/2017http://hdl.handle.net/1885/138089Crop yields could be significantly enhanced by improving the catalytic properties of the photosynthetic CO2-fixing enzyme Rubisco. Rubisco requires multiple chaperones to fold and maintain activity which has inhibited attempts to replace it with more efficient Rubisco�s from other photosynthetic species (Whitney et al 2015). One chaperone of interest for Rubisco biogenesis is the Bundle Sheath Defective 2 (BSD2) protein which when knocked out in maize has been shown to be seedling lethal due to a lack of Rubisco accumulation (Brutnell et al 1999). BSD2 contains a cysteine rich zinc finger domain related to that found in the chaperone DnaJ and has been found to co-fractionate with polyribosomes synthesising the Rubisco large subunit (Brutnell et al. 1999; Doron et al. 2014). In our studies of BSD2 function we have determined that BSD2 is specific for Rubisco biogenesis and does not have any other critical function in plants. We have found that overexpression does not enhance plant growth whilst knockdown of BSD2 results in almost total loss of Rubisco biogenesis. We found that in plant lines overexpressing BSD2 it is associated with the active Rubisco heterooligomer complex made up of 8 large subunits and 8 small subunits. BSD2 appears as a multimer in vitro and this multimerization can be prevented by mutating residue K47A in a loop thought to be associated with protein-protein interactions. This work has produced a range of insights into BSD2 function in Rubisco biogenesis.1 pageapplication/pdfen-AUAuthor/s retain copyright2017