3HYB

Crystal structure of RbcX from Anabaena, crystal form II

Summary for 3HYB

• Entry DOI: 10.2210/pdb3hyb/pdb
• Related: 2PEO
• Descriptor: RbcX protein, SULFATE ION (3 entities in total)
• Functional Keywords: rubisco, protein complex assembly, chaperone
• Biological source: Anabaena sp.
• Total number of polymer chains: 2
• Total formula weight: 35485.92

Authors

Bracher, A.,Liu, C. (deposition date: 2009-06-22, release date: 2010-01-19, Last modification date: 2023-09-06)

Primary citation

Liu, C.,Young, A.L.,Starling-Windhof, A.,Bracher, A.,Saschenbrecker, S.,Rao, B.V.,Rao, K.V.,Berninghausen, O.,Mielke, T.,Hartl, F.U.,Beckmann, R.,Hayer-Hartl, M.
Coupled chaperone action in folding and assembly of hexadecameric Rubisco.
Nature, 463:197-202, 2010

PubMed Abstract: Form I Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase), a complex of eight large (RbcL) and eight small (RbcS) subunits, catalyses the fixation of atmospheric CO(2) in photosynthesis. The limited catalytic efficiency of Rubisco has sparked extensive efforts to re-engineer the enzyme with the goal of enhancing agricultural productivity. To facilitate such efforts we analysed the formation of cyanobacterial form I Rubisco by in vitro reconstitution and cryo-electron microscopy. We show that RbcL subunit folding by the GroEL/GroES chaperonin is tightly coupled with assembly mediated by the chaperone RbcX(2). RbcL monomers remain partially unstable and retain high affinity for GroEL until captured by RbcX(2). As revealed by the structure of a RbcL(8)-(RbcX(2))(8) assembly intermediate, RbcX(2) acts as a molecular staple in stabilizing the RbcL subunits as dimers and facilitates RbcL(8) core assembly. Finally, addition of RbcS results in RbcX(2) release and holoenzyme formation. Specific assembly chaperones may be required more generally in the formation of complex oligomeric structures when folding is closely coupled to assembly.

PubMed: 20075914
DOI: 10.1038/nature08651

Experimental method

X-RAY DIFFRACTION (2.3 Å)