The MpsAB Bicarbonate Transporter Is Superior to Carbonic Anhydrase in Biofilm-Forming Bacteria with Limited CO ₂ Diffusion

Abstract

CO 2 and bicarbonate are required for carboxylation reactions in central metabolism and biosynthesis of small molecules in all bacteria. This is achieved by two different systems for dissolved inorganic carbon supply (DICS): these are the membrane potential-generating system (MpsAB) and the carbonic anhydrase (CA), but both rarely coexist in a given species.

Staphylococcus aureus Genomes Harbor Only MpsAB-Like Bicarbonate Transporter but Not Carbonic Anhydrase as Dissolved Inorganic Carbon Supply System

“…In our previous work, we showed that Staphylococcus carnosus harbors only a CA gene and confirmed that the protein is functional ( 8 ). As there was no S. carnosus -specific CA homolog present in S. aureus , we deduced that MpsAB functions as the sole CO 2 /bicarbonate concentration system in S. aureus .…”

“…Using the IMG/M database, pairwise average nucleotide identity (ANI) with two finished S. sciuri genomes revealed that C0673 has 97% nucleotide identity with S. sciuri SNUDS-18 and 96% nucleotide identity with S. sciuri FDAARGOS_285. C0673 is wrongly annotated as S. aureus in NCBI database, which gave us false-positive hits in our BLASTp because S. sciuri but not S. aureus has a CA as stated in Table 1 and our previous work ( 8 ).…”

“…To demonstrate the reliability of Pfam motifs, we performed protein-protein Basic Local Alignment Search Tool search (BLASTp) of the protein sequence of an experimentally confirmed CA from Staphylococcus carnosus ( 8 ) against fully sequenced (finished) representative strains from the genus Staphylococcus . The presence of CAs based on Pfam motif correlated with the high percentage of protein identity from S. carnosus CA ( Table 1 ).…”

“…In this regard, these bacteria utilize the enzyme carbonic anhydrase (CA) as a d issolved i norganic c arbon s upply (DICS) system ( 3 , 5 ) and the more recently described bicarbonate transporter MpsAB ( m embrane p otential generating s ystem) in Staphylococcus aureus ( 4 ). MpsAB is present not only in autotrophic bacteria such as Hydrogenovibrio crunogenus , Nitrobacter winogradskyi ( 6 ), and Halothiobacillus neapolitanus ( 7 ) but also in many nonautotrophic bacteria, like some strains of Bacillus subtilis , Legionella pneumophila , and Vibrio cholerae ( 6 , 8 ). MpsAB works alone and/or together with CA function to supply bicarbonate for anaplerotic reactions.…”

From annotation to bacterial data models

“…The latest updates reflect intensive research to identify novel transporters in B. subtilis. These include transporters for bicarbonate (NdhF-YbcC)(S. H. Fan et al, 2019;S.-H. Fan et al, 2021) and several amino acids including alanine (AlaP), glutamate and serine (both AimA) as well as the toxic analogon glyphosate (GltT) (Klewing et al, 2020;Krüger et al, 2021;Sidiq et al, 2021;Wicke et al, 2019).…”