9.B.370.  The Uncharacterized 1 N-terminal TMS (U1TMS) Family 

These proteins are of about 200 - 300 aas in length and have one N-terminal TMS, probably a signal TMS for export across the cytoplasmic membrane.  These proteins are found predominantly in bacteria. They were orignally thought to be related to Family PE-PPE (TC#1.B.89), but this does not seem to be true.