3RG6

Crystal structure of a chaperone-bound assembly intermediate of form I Rubisco

Summary for 3RG6

• Entry DOI: 10.2210/pdb3rg6/pdb
• Related: 1RBL 2PEO 2WVW 3HYB
• EMDB information: 1655
• Descriptor: Ribulose bisphosphate carboxylase large chain, RbcX protein (2 entities in total)
• Functional Keywords: photosynthesis, assembly chaperone, tim barrel (rbcl), carbon fixation (rbcl) complex assembly, protein folding, chaperone (rbcx), rbcs (rbcl)
• Biological source: Synechococcus elongatus; More
• Total number of polymer chains: 6
• Total formula weight: 175812.93

Authors

Bracher, A.,Starling-Windhof, A.,Hartl, F.U.,Hayer-Hartl, M. (deposition date: 2011-04-07, release date: 2011-07-20, Last modification date: 2024-11-20)

Primary citation

Bracher, A.,Starling-Windhof, A.,Hartl, F.U.,Hayer-Hartl, M.
Crystal structure of a chaperone-bound assembly intermediate of form I Rubisco.
Nat.Struct.Mol.Biol., 18:875-880, 2011

PubMed Abstract: The form I Rubisco of autotrophic bacteria, algae and plants is a complex of eight large (RbcL) and eight small (RbcS) subunits. It fixes atmospheric CO(2) in the dark reaction of photosynthesis. As shown for the cyanobacterial enzyme, folding of the RbcL subunits is mediated by the GroEL-GroES chaperonin system, and assembly requires the specialized chaperone RbcX, a homodimer of ~15-kDa subunits. Here we present the 3.2-Å crystal structure of a Rubisco assembly intermediate, consisting of the RbcL(8) core with eight RbcX(2) molecules bound. The structure reveals the molecular mechanism by which RbcX(2) mediates oligomeric assembly. Specifically, RbcX(2) provides positional information for proper formation of antiparallel RbcL dimers, thereby preventing RbcL-RbcL misalignment and off-pathway aggregation. The RbcL(8)(RbcX(2))(8) structure also suggests that RbcS functions by stabilizing the '60s loop' of RbcL in the catalytically active conformation.

PubMed: 21765418
DOI: 10.1038/nsmb.2090

Experimental method

X-RAY DIFFRACTION (3.2 Å)