Molecular genetics of the VDAC ion channel: Structural model and sequence analysis

The voltage-dependent anion-selective channel of the outer mitochondrial membrane provides a unique system in which to study the molecular basis of voltage gating of ion flow. We have cloned and sequenced acDNA coding for this protein in yeast. From the derived amino acid sequence, we have generated a preliminary model for the secondary structure of the protein which suggests that the protein forms a "β-barrel" type structure. Comparison of the VDAC amino acid sequence with that of the bacterial porins has indicated that the two classes of molecules appear to be unrelated.