Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis.Lou, K.L., Saint, N., Prilipov, A., Rummel, G., Benson, S.A., Rosenbusch, J.P., Schirmer, T.
(1996) J Biol Chem 271: 20669-20675
- PubMed: 8702816
- Primary Citation of Related Structures:
1GFO, 1GFN, 1GFM, 1GFQ, 1GFP
- PubMed Abstract:
- Crystal Structures Explain Functional Properties of Two E.Coli Porins
Cowan, S.W., Schirmer, T., Rummel, G., Steiert, M., Ghosh, R., Pauptit, R.A., Jansonius, J.N., Rosenbusch, J.P.
(1992) Nature 358: 727
- Mutations that Alter the Pore Function of the Ompf Porin of Escherichia Coli K12
Benson, S.A., Occi, J.L., Sampson, B.A.
(1988) J Mol Biol 203: 961
OmpF porin is a nonspecific pore protein from the outer membrane of Escherichia coli. Previously, a set of mutants was selected that allow the passage of long maltodextrins that do not translocate through the wild-type pore. Here, we describe the cry ...
OmpF porin is a nonspecific pore protein from the outer membrane of Escherichia coli. Previously, a set of mutants was selected that allow the passage of long maltodextrins that do not translocate through the wild-type pore. Here, we describe the crystal structures of four point mutants and one deletion mutant from this set; their functional characterization is reported in the accompanying paper (Saint, N., Lou, K.-L., Widmer, C., Luckey, M., Schirmer, T., Rosenbusch, J. P. (1996) J. Biol. Chem. 271, 20676-20680). All mutations have a local effect on the structure of the pore constriction and result in a larger pore cross-section. Substitution of each of the three closely packed arginine residues at the pore constriction (Arg-42, Arg-82, and Arg-132) by shorter uncharged residues causes rearrangement of the adjacent basic residues. This demonstrates mutual stabilization of these residues in the wild-type porin. Deletion of six residues from the internal loop (Delta109-114) results in disorder of seven adjacent residues but does not alter the structure of the beta-barrel framework. Thus, the large hollow beta-barrel motif can be regarded as an autonomous structure.
Department of Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.