Journal of Bioenergetics and Biomembranes

, Volume 29, Issue 6, pp 525–531

On the Structure and Gating Mechanism of the Mitochondrial Channel, VDAC

  • Carmen A. Mannella

DOI: 10.1023/A:1022489832594

Cite this article as:
Mannella, C.A. J Bioenerg Biomembr (1997) 29: 525. doi:10.1023/A:1022489832594


There is considerable evidence that the voltage-gated mitochondrial channel VDAC forms a β-barrel pore. Inferences about the number and tilt of β-strands can be drawn from comparisons with bacterial β-barrel pores whose structures have been determined by x-ray crystallography. A structural model for VDAC is proposed (based on sequence analysis and electron crystallography) in which the open state is like that of bacterial porins with several important differences. Because VDAC does not occur as close-packed trimers, there are probably fewer interpore contacts than in the bacterial porins. VDAC also appears to lack a large, fixed intraluminal segment and may not have as extensive a region of uniformly 35°-tilted β-strands as do the bacterial porins. These structural differences would be expected to render VDAC's β-barrel less stable than its bacterial counterparts, making major conformational changes like those associated with gating more energetically feasible. A possible gating mechanism is suggested in which movement of the N-terminal α-helix out of the lumen wall triggers larger-scale structural changes.

Porin ion channel mitochondria VDAC electron microscopy sequence analysis β-barrel 

Copyright information

© Plenum Publishing Corporation 1997

Authors and Affiliations

  • Carmen A. Mannella
    • 1
    • 2
  1. 1.Division of Molecular MedicineWadsworth Center, New York State Department of HealthAlbany
  2. 2.Department of Biomedical Sciences, School of Public HealthUniversity at Albany (SUNY)Albany

Personalised recommendations