In certain bacterial families this protein is expressed from the ydbH gene, and there is a suggestion that this is a form of DctA or dicarboxylate transport protein. Dicarboxylate transport proteins are found in aerobic bacteria which grow on succinate or other C4-dicarboxylates [1].

1: C4-dicarboxylate carriers and sensors in bacteria. Janausch IG, Zientz E, Tran QH, Kroger A, Unden G; Biochim Biophys Acta 2002;1553:39-56. PMID:11803016