Family of bacterial proteins that are likely to be part of the Na(+)-dependent bicarbonate transporter (sbt) family. Members carry 10TMS in a 5+5 duplicated structure. The loop between helices 5 and 6 in Synechocystis PCC6803 is likely to be the location for regulatory mechanisms governing the activation of the transporter [1].

1: Membrane topology of the cyanobacterial bicarbonate transporter, SbtA, and identification of potential regulatory loops. Price GD, Shelden MC, Howitt SM; Mol Membr Biol. 2011;28:265-275. PMID:21688970