PDBsum entry 1gfp

Transmembrane protein

PDB id: 1gfp

Contents

Protein chain

340 a.a. *

Ligands

C8E ×12

Waters ×149

* Residue conservation analysis

PDB id:

1gfp

Name:

Transmembrane protein

Title:

Ompf porin (mutant r42c)

Structure:

Matrix porin outer membrane protein f. Chain: a. Synonym: matrix porin, ompf porin. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 562. Strain: ib 910. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Trimer (from PDB file)

Resolution:

2.70Å R-factor: 0.164

Authors:

K.-L.Lou,T.Schirmer

Key ref:

K.L.Lou et al. (1996). Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis. J Biol Chem, 271, 20669-20675. PubMed id: 8702816 DOI: 10.1074/jbc.271.34.20676

Date:

08-May-96 Release date: 07-Dec-96

Protein chain

P02931  (OMPF_ECOLI) -  Outer membrane porin F from Escherichia coli (strain K12)

Seq: 362 a.a.

Struc: 340 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.271.34.20676

J Biol Chem 271:20669-20675 (1996)

PubMed id: 8702816

Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis.

K.L.Lou, N.Saint, A.Prilipov, G.Rummel, S.A.Benson, J.P.Rosenbusch, T.Schirmer.

ABSTRACT

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.

Selected figure(s)

Figure 3.
Fig. 3. Stereo diagram of the model of porin mutant R42C with partial wild-type model superimposed. Only those side chains of the wild-type model that differ significantly from the mutant model (Arg-42 and Arg-82) are shown (in brown). The view is similar to that in Fig. 1.

Figure 4.
Fig. 4. Stereo diagrams of porin mutant R82C. a, 2F[o] F[c] electron density (contoured at 1 ) with model superimposed. b, model of R82C with partial wild-type model superimposed. Only those side chains of the wild-type model that differ significantly from the mutant model (Arg-42, Lys-80, Arg-82, and Arg-132) are shown (in brown). Both conformations of Lys-80 are shown (see text). Magenta, major conformation with side chain amino group forming a salt-bridge with Cys-82 (see also a); yellow, minor conformation.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (1996, 271, 20669-20675) copyright 1996.

Figures were selected by an automated process.