- Title
- Cyanobacterial α-carboxysome carbonic anhydrase is allosterically regulated by the Rubisco substrate RuBP
- Creator
- Pulsford, Sacha B.; Outram, Megan A.; Förster, Britta; Rhodes, Timothy; Williams, Simon J.; Badger, Murray R.; Price, G. Dean; Jackson, Colin J.; Long, Benedict M.
- Relation
- Science Advances Vol. 10, Issue 19, no. eadk7283
- Publisher Link
- http://dx.doi.org/10.1126/sciadv.adk7283
- Publisher
- American Association for the Advancement of Science (AAAS)
- Resource Type
- journal article
- Date
- 2024
- Description
- Cyanobacterial CO2 concentrating mechanisms (CCMs) sequester a globally consequential proportion of carbon into the biosphere. Proteinaceous microcompartments, called carboxysomes, play a critical role in CCM function, housing two enzymes to enhance CO2 fixation: carbonic anhydrase (CA) and Rubisco. Despite its importance, our current understanding of the carboxysomal CAs found in α-cyanobacteria, CsoSCA, remains limited, particularly regarding the regulation of its activity. Here, we present a structural and biochemical study of CsoSCA from the cyanobacterium Cyanobium sp. PCC7001. Our results show that the Cyanobium CsoSCA is allosterically activated by the Rubisco substrate ribulose-1,5-bisphosphate and forms a hexameric trimer of dimers. Comprehensive phylogenetic and mutational analyses are consistent with this regulation appearing exclusively in cyanobacterial α-carboxysome CAs. These findings clarify the biologically relevant oligomeric state of α-carboxysomal CAs and advance our understanding of the regulation of photosynthesis in this globally dominant lineage.
- Subject
- Cyanobacterial CO2 concentrating mechanisms (CCMs); carbonic anhydrase (CA); Rubisco; photosynthesis
- Identifier
- http://hdl.handle.net/1959.13/1505083
- Identifier
- uon:55618
- Identifier
- ISSN:2375-2548
- Rights
- x
- Language
- eng
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