This family includes a number of K+ ion channel beta chain regulatory domains - these are reported to have oxidoreductase activity [2].

1: Refined 1.8 A structure of human aldose reductase complexed with the potent inhibitor zopolrestat. Wilson DK, Tarle I, Petrash JM, Quiocho FA; Proc Natl Acad Sci U S A 1993;90:9847-9851. PMID:8234324

2: Structure of the cytoplasmic beta subunit-T1 assembly of voltage-dependent K+ channels. Gulbis JM, Zhou M, Mann S, MacKinnon R; Science 2000;289:123-127. PMID:10884227