9.B.102 The YedE/YeeE (YeeE) Family
The YeeE family (also called the COG2392 or DUF395 family) consists of numerous putative transport proteins of from 4 to 10 TMSs (G Madrigal, P Kabran and M Saier, unpublished observations). Some of these (i.e PmpA and PmpB, both of 4 TMSs) may function together as a heterodimeric transporter. In some cases, two YeeE homologues are encoded in a single operon with a member of the TSUP family e.g., PmpC (2.A.102.4.2; Gristwood et al., 2011). Some evidence suggests that some of these proteins may play a role in sulfur and/or selenium metabolism (Lin et al. 2015). The smaller proteins (4 - 6 TMSs) have one of two conserved, related motifs, A or B, while the larger proteins (9 - 10 TMSs) have both in either of the two possible orders, A - B or B - A within two repeat segemnts of 5 TMSs (unpublished results).