7ZC1

Subtomogram averaging of Rubisco from Cyanobium carboxysome

Summary for 7ZC1

• Entry DOI: 10.2210/pdb7zc1/pdb
• EMDB information: 14589 14590 14592 14593 14617
• Descriptor: Ribulose bisphosphate carboxylase large chain, Ribulose bisphosphate carboxylase, small subunit (2 entities in total)
• Functional Keywords: rubisco, alpha carboxysomes, unknown function
• Biological source: Cyanobium sp. PCC 7001; More
• Total number of polymer chains: 16
• Total formula weight: 523953.14

Authors

Ni, T.,Zhu, Y.,Seaton-Burn, W.,Zhang, P. (deposition date: 2022-03-25, release date: 2022-07-06, Last modification date: 2024-07-24)

Primary citation

Ni, T.,Sun, Y.,Burn, W.,Al-Hazeem, M.M.J.,Zhu, Y.,Yu, X.,Liu, L.N.,Zhang, P.
Structure and assembly of cargo Rubisco in two native alpha-carboxysomes.
Nat Commun, 13:4299-4299, 2022

PubMed Abstract: Carboxysomes are a family of bacterial microcompartments in cyanobacteria and chemoautotrophs. They encapsulate Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase catalyzing carbon fixation inside a proteinaceous shell. How Rubisco complexes pack within the carboxysomes is unknown. Using cryo-electron tomography, we determine the distinct 3D organization of Rubisco inside two distant α-carboxysomes from a marine α-cyanobacterium Cyanobium sp. PCC 7001 where Rubiscos are organized in three concentric layers, and from a chemoautotrophic bacterium Halothiobacillus neapolitanus where they form intertwining spirals. We further resolve the structures of native Rubisco as well as its higher-order assembly at near-atomic resolutions by subtomogram averaging. The structures surprisingly reveal that the authentic intrinsically disordered linker protein CsoS2 interacts with Rubiscos in native carboxysomes but functions distinctively in the two α-carboxysomes. In contrast to the uniform Rubisco-CsoS2 association in the Cyanobium α-carboxysome, CsoS2 binds only to the Rubiscos close to the shell in the Halo α-carboxysome. Our findings provide critical knowledge of the assembly principles of α-carboxysomes, which may aid in the rational design and repurposing of carboxysome structures for new functions.

PubMed: 35879301
DOI: 10.1038/s41467-022-32004-w

Experimental method

ELECTRON MICROSCOPY (3.8 Å)