TCDB is operated by the Saier Lab Bioinformatics Group

9.B.330.  The DUF4013 (DUF4013) Family 

These proteins appear to occur as single proteins encoded by genes adjacent to genes of unrelated apparent functions, but sometimes they are adjacent to another membrane protein of similar seqence.     In several systems examined, ABC-type ATPases do not appear to occur within the same operon. These proteins are found in Archaea and Bacteria. They can have from 4 to 6 TMSs, and sometimes have hydrophilic extensions.