TCDB is operated by the Saier Lab Bioinformatics Group

1.A.113.  The Small Integral Membrane Protein (SIMP) Family

Members of the Small Integral Membrane Protein (SIMP) Family usually have just one TMS, but one of them (TC# 1.A.113.1.3) has two TMSs due to an internal duplication.  They may be homologous to proteins of the same sizes and topologies as the members of families 1.A.50, 1.A.95 and 1.A.100.