9.B.272. The Uncharacterized Protein from Uncultivated Bacteria-9 (UPUB9) Family
This family includes small protein of about 170 to 210 aas, usually with 5 TMSs. They are found exclusively in uncultured bacteria. However, with an iteration with NCBI Psi-Blast, the dominant proteins that come up are amino acid transport membrane proteins of the ABC superfamily with TC# 3.A.1.3. These integral membrae ABC proteins show variable numbers of TMSs, but many have 5 TMSs.