9.B.120 The DUF554 (DUF554) Family Members of the DUF554 family probably have 8 TMSs in a 3 + 5 TMS arrangement. They have about 235 aas. Also called the PF04474 or COG1811 family. All are from prokaryotes. These proteins may be distantly related to the DMT family (TC# 2.A.7) which have 10 TMSs with a 5 TMS repeat unit. The DUF554 family members consistantly have a 3 + 5 TMS topology where the 5 TMS unit may be related to members of the DMT superfamily.
This family belongs to the Drug/Metabolite Transporter (DMT) Superfamily.
Examples:
TC#	Name	Organismal Type	Example
9.B.120.1.1	PFO4474 family protein, YqgA	Bacteria	*YqgA of E. coli* (Q46831)**

9.B.120.1.2	Putative transport protein of 7 or 8 TMSs	Bacteria	*Transport protein of Bacillus subtilis* (G4P6M9)**

9.B.120.1.3	Hypothetical protein of 7-8 TMSs	Bacteria	*HP of Thermus thermophilus* (Q5SJX5)**

9.B.120.1.4	Transporter of 7-8 TMSs	Bacteria	*Transporter of Lactobacillus amylovorus* (F2M2W9)**

9.B.120.1.5	Hypothetical protein of 256 aas and 8 TM	Bacteria	*HP of Deinococcus proteolyticus* (F0RPM5)**

9.B.120.1.6	Hypothetical protein of 7-8 TMSs	Cyanobacteria	*HP of Cyanobium* sp. PCC 7001 (B5IQA5)**

9.B.120.1.7	Uncharacterized protein of 222 aas and 8 TMSs in a 3 + 5 TMS arrangement.		UP of Thermofilum pendens

9.B.120.1.8	DUF554 protein, YdfK, of 228 aas and probably 8 TMSs in a 3 + 5 TMS arrangement, possibly related to TC family 2.A.7 (DMT superfamily)		YdfK of Desulfonauticus submarinus

9.B.120.1.9	DUF554 domain-containing protein of 270 aas and 8 TMSs in a 3 + 5 TMS arrangement.		DUF554 protein of Natranaerobius thermophilus