Permease SLC13 (solute carrier 13). The sodium/dicarboxylate cotransporter NaDC-1 has been shown to translocate Krebs cycle intermediates such as succinate, citrate, and alpha-ketoglutarate across plasma membranes rabbit, human, and rat kidney. It is related to renal and intestinal Na+/sulfate cotransporters and a few putative bacterial permeases. The SLC13-type proteins belong to the ArsB/NhaD superfamily of permeases that translocate sodium and various anions across biological membranes in all three kingdoms of life. A typical ArsB/NhaD permease is composed of 8-13 transmembrane helices.