2.A.135.1.5
DUF1538 domain protein of 255 aas and 7 TMSs. This protein brings up 2.A.63.1.3 (residues 10 - 251 (TMSs 1 - 7) aligning with residues 157 - 391 aas (TMSs 4 - 9) in 2.A.63.1.3 which has 14 TMSs.  It is possible that these two families are part of a superfamily, but this possibility has not yet been tested rigorously. However, if homologous, this suggests that there was a rearrangement between the two families so that TMSs 1 - 7 in this protein corresponds to TMS 4 - 10 in MnhD (P60686) in the multisubunit Mnh cation exchanger (2.A.63.1.3).  The fact that both systems catalyze the same reaction also suggests that these two families are part of a superfamily.