2.A.120 The Putative Amino Acid Permease (PAAP) Family
The PAAP family consists of many proteins all of a uniform topology with a 5 + 5 TMS repeat in a 2 + 3 + 2 + 3 arrangement. These proteins show similarity to members of the LIVCS family (TC# 2.A.26) in the APC Superfamily (Vastermark et al. 2014). There does not seem to be a single member that has been functionally characterized as of 8/2014. However, a large majority of the genes encoding these transporters occur in operons or gene clusters encoding enzymes of amino acid metabolism. These incude proteases, sporulation proteins, amino acid aminotransferases, amino acid and oxo acid oxidoreductases, and amino acid tRNA synthetases.