9.B.124 The DUF805 or PF05656 (DUF805) Family
The DUF805 family consists of small proteins (~ 110 to 180aas) with 3 or 4 TMSs. In E. coli, YhaH and YhaI are homologous proteins that are encoded by adjacent genes. They may encode a complete transport system as is often the case with SMR members of the DMT superfamily which can be either homodimeric or heterodimeric. In the latter case, the two homologoous genes usually map next to each other (Jack et al. 2001).