9.B.333.  The Uncharacterized Archaeal/Bacterial 5 TMS (UAB5) Family 

Members of this family are found in archaea and bacteria and can be associated with sensor histidine kinase and response regulator domains, and probably with other domains as well. Some members of the family have 5 C-terminal TMSs and an N-terminal hydrophilic domain that is likely to play a role in transcriptional regulation.  In fact, the majority of characterized NCBI Blast hits seem to function in transcriptional control. 9.B.333.1.2 may be distantly related to 9.B.29.2.13 and 9.B.346.3.2, but homology has not been established. The first two of these proteins have 5 TMSs in a 1 + 2 + 2 TMS arrangement, but the last of these proteins is a 4 TMS protein.