Diameter of Rubisco core complex (RbcL8)

Value ~110 Å
Organism Cyanobacteria Synechococcus sp. PCC6301
Reference Cuimin Liu, Anna L. Young, Amanda Starling-Windhof, Andreas Bracher, Sandra Saschenbrecker, Bharathi Vasudeva Rao, Karnam Vasudeva Rao, Otto Berninghausen, Thorsten Mielke, F. Ulrich Hartl, Roland Beckmann & Manajit Hayer-Hartl. Coupled chaperone action in folding and assembly of hexadecameric Rubisco. Nature. 2010 Jan 14 463(7278):197-202. p.197 left column top paragraphPubMed ID20075914
Method Cyanobacterial Rubisco from Synechococcus sp. PCC6301 (Syn6301) was reconstituted in E. coli in vitro using the GroEL/GroES and RbcX2 chaperone systems. RbcL complex was analysed by cryoelectron microscopy. In cryo-electromicroscopy the specimen is cooled to cryogenic (very cool, under 123 Kelvin) temperatures, without fixing or staining it in any way. This is said to prevent the deformations which may be caused in non physiological conditions by other techniques such as in x ray crystallography. As seen from the cryo-EM density map at ~16Å resolution (Supplementary Fig. 6a, b), the RbcL8 complex has a diameter of ~110Å, consistent with the size of the RbcL8 core in the RbcL8S8 crystal structure, but a height of only ~75Å , that is, ~25Å less than the holoenzyme core.
Comments Rubisco in plants and cyanobacteria has a complex oligomeric structure consisting of eight large (RbcL, ~50 kDa) and eight small (RbcS, ~15 kDa) subunits. The RbcL subunits arrange as a tetramer of catalytic anti-parallel dimers (the RbcL8 core complex), capped by four RbcS subunits at the top and bottom, respectively. The oligomer has a cylindrical shape with a diameter of ~110Å and a height of 100Å. See BNID 101679, 105125
Entered by Uri M
ID 103861