9.B.116 The Transporter, YvqF (YvqF) Family

The YvqF family includes thousands of sequenced proteins, all of which have an N-terminal transmembrane domain of probably of 2-4 TMSs (residues 1-~120) plus a C-terminal hydrophilic Duf2154 domain that includes a central semihydrophobic region of about 50 residues that is sometimes predicted to comprise an additional 2 TMSs. An example is YvqF of Streptococcus dysgalactiae (9.B.116.1.1). The Duf2154 domain may contain an internal repeat of about 44 aas. The function is unknown. However, this family may show some sequence similarity with the 2-TMS TC family 9.B.109, a family of putative archaeal holins.