9.B.344. The Uncharacterized Archaeal 4 TMS Protein (UA4P) Family The proteins of the UA4P family are usually about 200 aas in length and have 4 TMSs often in a 1 +2 + 1 TMS arrangement. They are found exclusively in archaea, mostly in Lokiarchaeota and Methanomassiliicoccus species. In the latter organisms, there are both 4 and 8 TMS proteins. In the latter, the two halves are both homologous to the 4 TMS proteins. This provides evidence that these proteins may be transporters that function as homodimers of two 4 TMS proteins or as monomers of the 8 TMS proteins. .
Examples:
TC#	Name	Organismal Type	Example
9.B.344.1.1	UP of 218 aas and 4 TMSs with a XrtN domain		UP of Candidatus Lokiarchaeota archaeon CR_4

9.B.344.1.2	Uncharacterized protein of 181 aas and 4 TMSs		UP of Candidatus Lokiarchaeota archaeon (sediment metagenome)

Examples:
TC#	Name	Organismal Type	Example
9.B.344.2.1	Uncharacterized protein of 167 aas and 4 TMSs		UP of Methanomassiliicoccales archaeon PtaU1.Bin030 (bioreactor metagenome)

9.B.344.2.10	Uncharacterized protein of 185 aas and 4 TMSs.		UP of Methanomassiliicoccales archaeon Mx-06 (human gut metagenome)

9.B.344.2.2	Uncharacterized protein of 171 aas and 4 TMSs.		UP of Methanomassiliicoccus luminyensis

9.B.344.2.3	Uncharacterized protein of 378 aas and 8 TMSs in a 4 + 4 TS arrangement.		UP of Methanomassiliicoccus sp. (marine sediment metagenome)

9.B.344.2.4	Uncharacterized protein of 166 aas and 4 TMSs.		*UP of Candidatus Methanomassiliicoccus intestinalis* (human gut metagenome)**

9.B.344.2.5	Uncharacterized protein of 243 aas and 4 N-terminal TMSs with a C-terminal hydrophilic extension of about 100 aas.		UP of Euryarchaeota archaeon (subsurface metagenome)

9.B.344.2.6	Uncharacterized protein of 157 aas and 4 TMSs		*UP of Thermoplasmata* archaeon**

9.B.344.2.7	Uncharacterized protein of152 aas and 4 TMSs		UP of an unidentified uncultured organism

9.B.344.2.8	Uncharacterized protein of 200 aas and 4 TMSs in a 1 + 2 + 1 TMS arrangement.		UP of Methanomassiliicoccales archaeon Mx-02 (human gut metagenome)

9.B.344.2.9	Uncharacterized protein of 313 aas with 5 TMSs in a 3 + 1 TMS arrangement with a 100 aa hydrophilic extention.		UP of Candidatus Lokiarchaeota archaeon (sediment metagenome)