Figure 2.

Possible subunit arrangements. (A) The two arrangements from coexpression of α and β monomers assume that heteromeric channels are tetramers with a 2:2 subunit stoichiometry. (B) The most likely heteromeric channel arrangements from α-β and β-α heterodimers. (C) Probable functional heteromeric channel arrangements, formed inefficiently from coexpressed α-α dimers with either β monomers or β-β dimers. (D) Proposed subunit arrangement of native bovine rod CNG channels.