5NV3

Structure of Rubisco from Rhodobacter sphaeroides in complex with CABP

Summary for 5NV3

• Entry DOI: 10.2210/pdb5nv3/pdb
• EMDB information: 3699
• Descriptor: Ribulose bisphosphate carboxylase large chain, Ribulose bisphosphate carboxylase small chain 1, 2-CARBOXYARABINITOL-1,5-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: beta barrel, lyase
• Biological source: Rhodobacter sphaeroides; More
• Total number of polymer chains: 16
• Total formula weight: 538660.05

Authors

Bracher, A.,Milicic, G.,Ciniawsky, S.,Wendler, P.,Hayer-Hartl, M.,Hartl, F.U. (deposition date: 2017-05-03, release date: 2017-07-26, Last modification date: 2025-04-09)

Primary citation

Bhat, J.Y.,Milicic, G.,Thieulin-Pardo, G.,Bracher, A.,Maxwell, A.,Ciniawsky, S.,Mueller-Cajar, O.,Engen, J.R.,Hartl, F.U.,Wendler, P.,Hayer-Hartl, M.
Mechanism of Enzyme Repair by the AAA(+) Chaperone Rubisco Activase.
Mol. Cell, 67:744-756.e6, 2017

PubMed Abstract: How AAA+ chaperones conformationally remodel specific target proteins in an ATP-dependent manner is not well understood. Here, we investigated the mechanism of the AAA+ protein Rubisco activase (Rca) in metabolic repair of the photosynthetic enzyme Rubisco, a complex of eight large (RbcL) and eight small (RbcS) subunits containing eight catalytic sites. Rubisco is prone to inhibition by tight-binding sugar phosphates, whose removal is catalyzed by Rca. We engineered a stable Rca hexamer ring and analyzed its functional interaction with Rubisco. Hydrogen/deuterium exchange and chemical crosslinking showed that Rca structurally destabilizes elements of the Rubisco active site with remarkable selectivity. Cryo-electron microscopy revealed that Rca docks onto Rubisco over one active site at a time, positioning the C-terminal strand of RbcL, which stabilizes the catalytic center, for access to the Rca hexamer pore. The pulling force of Rca is fine-tuned to avoid global destabilization and allow for precise enzyme repair.

PubMed: 28803776
DOI: 10.1016/j.molcel.2017.07.004

Experimental method

ELECTRON MICROSCOPY (3.39 Å)