9.B.237. The Ubiquitous Uncharacterized 7 TMS Protein-1(UUP1) Family
This family consists of proteins from uncultured bacteria as well as well characterized bacterial and archaeal phyla. They all appear to have a single N-terminal TMS followed by a hydrophilic domain, either short (<50 residues) or long >300 residues, followed by a C-terminal 6 TMS domain, where all 6 TMSs appear to be present together, but in three groups of closely clustering sets of 2 TMSs. Some of these proteins may lack the N-terminal hydrophilic domain, thus having only 6 TMSs. Others have all 7 TMSs N-terminal with a long C-terminal hydrophilic domain. Many of these protein are annotated 'Gonadoliberin III-like protein' implying the presence of eukaryotic homologues.