Structure and assembly of cargo Rubisco in two native α-carboxysomes

DOI: 10.1038/s41467-022-32004-w

Authors: Tao Ni (Wellcome Centre for Human Genetics, University of Oxford) , Yaqi Sun (University of Liverpool) , Will Burn (Wellcome Centre for Human Genetics, University of Oxford) , Monsour M. J. Al-Hazeem (University of Liverpool) , Yanan Zhu (Wellcome Centre for Human Genetics, University of Oxford) , Xiulian Yu (Wellcome Centre for Human Genetics, University of Oxford) , Lu-Ning Liu (University of Liverpool; Ocean University of China) , Peijun Zhang (Diamond Light Source; Wellcome Centre for Human Genetics, University of Oxford; Chinese Academy of Medical Sciences Oxford Institute, University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 13

State: Published (Approved)
Published: July 2022
Diamond Proposal Number(s): 21004 , 20223 , 21005

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.

Subject Areas: Biology and Bio-materials

Diamond Offline Facilities: Electron Bio-Imaging Centre (eBIC)
Instruments: Krios III-Titan Krios III at Diamond

Added On: 01/08/2022 10:21

Documents:
s41467-022-32004-w.pdf

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Microscopy Electron Microscopy (EM) Cryo Electron Microscopy (Cryo EM)