Dataset for "Functional characterisation of bicarbonate transporters from the cyanobacterial SbtA2 family and subsequent expression in tobacco"

To use of this Ci source, cyanobacteria employ CO2 concentrating mechanisms (CCMs) that elevate cytoplasmic HCO3- via plasma membrane transporters, enhancing carboxylation by carboxysomal Rubisco. The sodium-dependent SbtA1 transporter family is well-characterized in freshwater cyanobacteria, but the related SbtA2 family, prevalent in marine α-cyanobacteria, remains uncharacterised.

Here, we report functional characterisation of SbtA2 homologues from marine Synechococcus spp., which exhibit high Ci uptake flux with apparent chloride dependence and intermediate HCO3- affinity (Km ≈ 150 µM), when assessed in E. coli. SbtA2 achieved internal Ci accumulation up to 24 mM within 30 seconds. Co-expression with the putative regulator SbtB2 reduced uptake activity, suggesting a regulatory role for this protein.