We have discovered a highly conserved family of putative membrane transporters required for growth at elevated pH, proper cell division and multidrug resistance in Escherichia coli. This family is called the DedA/Tvp38 family in public databases based upon similarity to Escherichia coli DedA and Saccharomyces cerevisiae SNARE-associated protein Tvp38. Currently, there are thousands of DedA family genes in the online database and they are present in most sequenced genomes. They display no significant amino acid identity to protein families of known function including all known membrane transporter families. YqjA and YghB from E. coli are partially redundant DedA family proteins with 62 % amino acid identity. In a series of publications, we have characterized an E. coli mutant named BC202 with nonpolar deletions of yghB and yqjA. We have shown that DedA proteins in E. coli and other organisms are required for proper cell division, growth, protonmotive force and drug and biocide resistance. The function of several DedA family proteins is absolutely dependent upon membrane embedded acidic amino acids glutamic acid and/or aspartic acid suggesting they belong to a new family of proton dependent transporters. We are currently exploring the roles of DedA family proteins in other Gram-negative bacterial species.