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DABs are inorganic carbon pumps found throughout prokaryotic phyla.

ABSTRACT: Bacterial autotrophs often rely on CO₂ concentrating mechanisms (CCMs) to assimilate carbon. Although many CCM proteins have been identified, a systematic screen of the components of CCMs is lacking. Here, we performed a genome-wide barcoded transposon screen to identify essential and CCM-related genes in the γ-proteobacterium Halothiobacillus neapolitanus. Screening revealed that the CCM comprises at least 17 and probably no more than 25 genes, most of which are encoded in 3 operons. Two of these operons (DAB1 and DAB2) contain a two-gene locus that encodes a domain of unknown function (Pfam: PF10070) and a putative cation transporter (Pfam: PF00361). Physiological and biochemical assays demonstrated that these proteins-which we name DabA and DabB, for DABs accumulate bicarbonate-assemble into a heterodimeric complex, which contains a putative β-carbonic anhydrase-like active site and functions as an energy-coupled inorganic carbon (C_i) pump. Interestingly, DAB operons are found in a diverse range of bacteria and archaea. We demonstrate that functional DABs are present in the human pathogens Bacillus anthracis and Vibrio cholerae. On the basis of these results, we propose that DABs constitute a class of energized C_i pumps and play a critical role in the metabolism of C_i throughout prokaryotic phyla.

SUBMITTER: Desmarais JJ

PROVIDER: S-EPMC10184468 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

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DABs are inorganic carbon pumps found throughout prokaryotic phyla.

Desmarais John J JJ Flamholz Avi I AI Blikstad Cecilia C Dugan Eli J EJ Laughlin Thomas G TG Oltrogge Luke M LM Chen Allen W AW Wetmore Kelly K Diamond Spencer S Wang Joy Y JY Savage David F DF

Nature microbiology 20190812 12

Bacterial autotrophs often rely on CO<sub>2</sub> concentrating mechanisms (CCMs) to assimilate carbon. Although many CCM proteins have been identified, a systematic screen of the components of CCMs is lacking. Here, we performed a genome-wide barcoded transposon screen to identify essential and CCM-related genes in the γ-proteobacterium Halothiobacillus neapolitanus. Screening revealed that the CCM comprises at least 17 and probably no more than 25 genes, most of which are encoded in 3 operons. ...[more]

PMID: 31406332

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DABs are inorganic carbon pumps found throughout prokaryotic phyla.

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DABs are inorganic carbon pumps found throughout prokaryotic phyla.

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