Cyanobacteria from marine oxygen-deficient zones encode both form I and form II Rubiscos

• 成果类型: Article
• 署名作者: Jaffe, Alexander L.; Harrison, Kaitlin; Wang, Renee Z.; Taylor-Kearney, Leah J.; Jain, Navami; Prywes, Noam; Shih, Patrick M.; Young, Jodi; Rocapb, Gabrielle; Dekas, Anne E.
• 署名单位: Stanford University; University of Washington; University of Washington Seattle; University of California System; University of California Berkeley; University of California System; University of California Berkeley; Stanford University; University of California System; University of California Berkeley; Howard Hughes Medical Institute; University of California System; University of California Berkeley; United States Department of Energy (DOE); Joint BioEnergy Institute - JBEI; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14604
• DOI: 10.1073/pnas.24183451
• 发表日期: 2024-12-03
• 关键词: prochlorococcus; proteobacteria

摘要

Cyanobacteria are highly abundant in the marine photic zone and primary drivers of the conversion of inorganic carbon into biomass. To date, all studied cyanobacterial lineages encode carbon fixation machinery relying upon form I Rubiscos within a CO2-concentrating carboxysome. Here, we report that the uncultivated anoxic marine zone (AMZ) IB lineage of Prochlorococcus from pelagic oxygen- deficient zones (ODZs) harbors both form I and form II Rubiscos, the latter of which are typically noncarboxysomal and possess biochemical properties tuned toward low- oxygen environments. We demonstrate that these cyanobacterial form II enzymes are functional in vitro and were likely acquired from proteobacteria. Metagenomic analysis reveals that AMZ IB are essentially restricted to ODZs in the Eastern Pacific, suggesting that form II acquisition may confer an advantage under low-O-2 conditions. AMZ IB populations express both forms of Rubisco in situ, with the highest form II expression at depths where oxygen and light are low, possibly as a mechanism to increase the efficiency of photoautotrophy under energy limitation. Our findings expand the diversity of carbon fixation configurations in the microbial world and may have implications for carbon sequestration in natural and engineered systems.