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9.B.424.  The Uncharacterized 6 TMS Protein (U6P) Family 

This family includes proteins, usually with ~200 aas and 6 TMSs in a 2 + 2 + 2 TMS arrangement.  It seems to be present only in Saccharibacteria, and few members are present in NCBI as of 8/6/2021.