Structural architecture of an outer membrane channel as determined by electron crystallography

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Abstract

PORINS are a family of membrane channels commonly found in the outer membranes of Gram-negative bacteria where they serve as diffusional pathways for waste products, nutrients and anti-biotics, and can also be receptors for bacteriophages1,2. Porin channels have been shown in vitro to be voltage-gated3–6. They can exhibit slight selectivities for certain solutes; for example PhoE porin has some selectivity for anionic and phosphate-containing compounds1,7. Unlike many known membrane proteins which often contain long stretches of hydrophobic segments that are believed to traverse the membrane in a helical conformation, porins are found to have charged residues distributed almost uniformly along their primary sequences and have most of their secondary structure in a β-sheet conformation8–10. We have made crystalline patches of PhoE porin embedded in a lipid bilayer and have used these to determine the structure of PhoE porin by electron crystallography to a resolution of 6Å. The basic structure consists of a trimer of elliptically shaped, cylindrical walls of β sheet. Each cylinder has an inner lining, formed by parts of the polypeptide, that defines the channel size. The structure provides a clue as to how deletions of segments of polypeptide, which are found in certain mutants, can result in an actual increase in the channel size.

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References

  1. 1

    Nikaido, H. & Vaara, M. Microbiol. Rev. 49, 1–32 (1985).

  2. 2

    Lugtenberg, B. & Van Alphen, L. Biochim biophys. Acta 737, 51–115 (1983).

  3. 3

    Schindler, H. & Rosenbusch, J. P. Proc natn. Acad. Sci. U.S.A. 75, 3751–3755 (1978).

  4. 4

    Dargent, B., Hofmann, W., Pattus, F. & Rosenbusch, J. P. EMBO J. 5, 773–778 (1986).

  5. 5

    Xu, G., Shi, B., McGroarty, E. J. & Tien, H. T. Biochim. biophys. Acta 862, 57–64 (1986).

  6. 6

    Mauro, A., Blake, M. & Labarca, P. Proc. natn. Acad Sci. U.S.A. 85, 1071–1075 (1988).

  7. 7

    Korteland, J., Tommassen, J. & Lugtenberg, B. Biochim biophys. Acta 690, 282–289 (1982).

  8. 8

    Rosenbusch, J. P. J. biol. Chem. 249, 8019–8029 (1974).

  9. 9

    Kleffel, B., Garavito, R. M., Baumeister, W. & Rosenbusch, J. P. EMBO J. 4, 1589–1592 (1985).

  10. 10

    Tommassen, J. Membrane Biogenesis NATO ASI Series Vol. 16 (ed. Op den Kamp J.A.F.) 351–373 (NATO 1988).

  11. 11

    Walian, P. J. & Jap, B. K. J. molec. Biol. 215, 429–438 (1990).

  12. 12

    Jap, B. K., Downing, K. H. & Walian, P. J. J. struct Biol. 103, 57–63 (1990).

  13. 13

    Downing, K. H. & Glaeser, R. M. Utramicroscopy 20, 269–278 (1986).

  14. 14

    Bullough, P. & Henderson, R. Ultramiscoscopy 21, 223–230 (1987).

  15. 15

    Shaw, P. J. & Hills, G. J. Micron 12, 279–282 (1981).

  16. 16

    Henderson, R. et al. J. molec Biol. 213, 899–929 (1990).

  17. 17

    Jap, B. K. J. molec. Biol. 205, 407–419 (1989).

  18. 18

    Agard, D. A. J. molec. Biol. 167, 849–852 (1983).

  19. 19

    Jap, B. K. & Walian, J. P. Q. Rev. Biophys. 23–4, 367–403 (1990).

  20. 20

    Misra, R. & Benson, S. A. J. Bact. 170, 3611–3617 (1988).

  21. 21

    Benson, S. A., Occi, J. L. L. & Sampson, B. A. J. molec. Biol. 203, 961–970 (1988).

  22. 22

    Hoenger, A., Gross, H., Aebi, U. & Engel, A. J. struct Biol. 103, 185–195 (1990).

  23. 23

    Nestel, U. et al. FEBS Lett 242, 405–408 (1989).

  24. 24

    Weiss, M. S. et al. FEBS Lett 256, 143–146 (1989).

  25. 25

    Weiss, M. S., Wacker, T., Weckesser, J., Welte, W. & Schulz, G. E. FEBS Lett. 267, 268–272 (1990).

  26. 26

    Sass, H. J. et al. J. molec. Biol. 209, 171–175 (1989).

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Jap, B., Walian, P. & Gehring, K. Structural architecture of an outer membrane channel as determined by electron crystallography. Nature 350, 167–170 (1991) doi:10.1038/350167a0

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