9.B.29 The small 4-5 TMS Putative Permease (4-5PP) Family
The 4-5PP family consists of proteins from Spirochaetes (Leptospira (subfamily 1)) and many potentially distant homologues in other bacteria (subfamilies 2 - 4) as well as archaea (subfamily 5). They have 200 - 270 aas with 4 - 5 TMSs. Some of them are encoded adjacent to genes coding for membrane fusion proteins (MFPs; 8.A.1) and outer menbrane factors (OMFs; 1.B.17) implying they are effulx systems. These proteins may be distantly related to but members of the ABC superfamily (3.A.1).