TCDB is operated by the Saier Lab Bioinformatics Group

9.B.265.  The Vitamin K Epoxide Reductase (VKER) Family 

The members of this family are between about 140 aas and about 600 aas in length. They have 4, 5 or 6 TMSs which for the small proteins encompase the whole protein, but for the larger proteins are always N-terminal.  They all show sequence similarity in their transmembrane domain, not in their C-terminal hydrophilic domains which are often very different in sequence.  Some have a C-terminal reductase domain and have been assigned to the bacterial VKER Family. Many clearly do not function in this capacity. There is no evidence that they function in transport.