Major proteins of the outer cell envelope membrane ofEscherichia coli K-12: Multiple species of protein I

Henning, Ulf; Schmidmayr, Waltraud; Hindennach, Ingrid

doi:10.1007/bf00571285

Cited by 86 publications

(49 citation statements)

References 25 publications

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“…A comparison of the overall amino acid composition of protein e with those of proteins b and c (table 2) shows many similarities but protein e contains relatively more asparagine and methionine and less arginine, valine and tyrosine than the two other proteins. The amino terminus is H,N-Ala-Glu as was also observed for proteins b and c [16,18,19].…”

Section: Comparison Ofpurifiedprotein E With Other Outer Membrane Prosupporting

confidence: 52%

“…Recently two other peptidoglycan-associated proteins were described which appear, like protein e, in b-c-strains [ 16,201. Protein Ic has the same electrophoretic mobility as protein b in the Laemmli get system [ 161 whereas protein E has about the same mobility as our e protein in the system described by us and seems to have pore properties for antibiotics [ZO].…”

Section: Comparisorr Oj'p?o Tein E With Protcim Ic and Ementioning

confidence: 99%

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Pore protein e of the outer membrane of escherichia coli K12

et al. 1978

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Section: Comparison Ofpurifiedprotein E With Other Outer Membrane Prosupporting

confidence: 52%

Section: Comparisorr Oj'p?o Tein E With Protcim Ic and Ementioning

confidence: 99%

Pore protein e of the outer membrane of escherichia coli K12

et al. 1978

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“…The OmpF and OmpA proteins, and the 'heat-modified' form of the OmpA protein, migrate with apparent M, values of 37000 [12], 33000 [lo] and 28000 [I31 respectively in this system. Fluorography was carried out with either En3Hance (New England Nuclear) [5] or sodium salicylate [14], using 'preflashed' films [15].…”

Section: Sodium Dodec~lsul~~hatelpol~at~r~~luniicie Gel Ekrtrophoresismentioning

confidence: 96%

Rate of Translation and Kinetics of Processing of Newly Synthesized Molecules of Two Major Outer‐Membrane Proteins, the OmpA and OmpF Proteins, of Escherichia coli K12

Crowlesmith¹,

Gamon²

1982

European Journal of Biochemistry

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The rate of synthesis of the OmpA and OmpF proteins, two of the major outer membrane proteins of E.sckerichia coli K12, was determined. At 25 "C both proteins were translated at 6.5 amino acids/s, and the OmpF protein was translated at 15 amino acids/s at 37 "C. The former rate corresponded to a synthesis time of just over SO s for both proteins, which is significantly faster than their reported rates of assembly into the outer membrane at 25 "C. The kinetics of processing of the pro-OmpF protein were also investigated in detail, and the pro-OmpF half-life estimated to be 3 -5 s at 25 "C. However a fraction of the precursor was processed more slowly, which may explain the discrepancy between these data and our earlier published estimate of 30 s. Pro-OnipA protein was processed with similar kinetics. These results demonstrate that the rate-limiting step in the assembly of both proteins into the outer membrane is post-translational and follows the processing step.The outer membrane proteins of gram-negative bacteria share a number of biosynthetic steps with two other classes of exported protein, the inner membrane and periplasmic proteins. These include: translation, export (i.e. transfer across the inner membrane) and processing (for proteins synthesized initially in precursor form). In addition, outer membrane proteins must be translocated to the outer membrane. Despite these similarities the rate of assembly of outer membrane proteins is two or three times slower than that of inner membrane proteins (though perhaps faster than that of periplasmic proteins) at 25-30 "C [I -41. Intuitively it would seem that the rate-limiting step in outer membrane protein assembly must be either translocation (the only step unique to outer membrane proteins) or processing (which should not affect the kinetics of inner membrane protein assembly). In an earlier paper [ S ] we reported that newly synthesized pro-OmpF protein had a relatively long half-life of 30 s, suggesting that the processing reaction might be ratelimiting for assembly. However, we also found that newly synthesized, processed molecules of both OmpF and OmpA proteins were present in the inner membrane after a 10-s pulse ; these results suggest that translocation may be rate-These results are at odds with those of Lin and Wu [2], who have suggested that the rate-limiting step in outer membrane protein assembly is translation of the niRNA. However, their evidence is indirect and not in accordance with the data of Boyd and Holland [6], who could detect no difference between the 'run-out' times (a crude measure of the translation rate) of the OmpF protein and a representative cytoplasmic protein in Escherichia coli Bjr.In view of these problems we decided to reinvestigate the kinetics of processing of the OmpF and OmpA proteins and to measure directly their rates of synthesis. Our results indicate that neither processing nor translation are slow enough to permit them to be considered rate-limiting. Since the only steps to follow processing are translocation and irre...

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“…Growth of E. coli under conditions of phosphate limitation results in derepression of the synthesis of a new outer membrane protein [8] which is antigenically related to the other two pore proteins [1]. This protein has previously been designated as protein Ic [9], e [10] or E [11] but should be named PhoE protein [12] as according to the new uniform nomenclature system these proteins are designated after their structural gene [ 13]. In addition to PhoE protein, the cell synthesizes a large number of other proteins [14,15] as a reaction on phosphate limitation, e.g.…”

Section: Introductionmentioning

confidence: 99%

PhoE protein pore of the outer membrane of Escherichia coli K12 is a particularly efficient channel for organic and inorganic phosphate

Korteland

Tommassen

Lugtenberg

1982

Biochimica et Biophysica Acta (BBA) - Biomembranes

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This study was undertaken to investigate the proposed in vivo pore function of PhoE protein, an Escherichia coil KI2 outer membrane protein induced by growth under phosphate limitation, and to compare it with those of the constitutive pore proteins OmpF and OmpC. Appropriate mutant strains were constructed containing only one of the proteins PhoE, OmpF or OmpC, or none of these proteins at all. By measuring rates of nutrient uptake at low solute concentrations, the proposed pore function of PhoE protein was confirmed as the presence of the protein facilitates the diffusion of Pi through the outer membrane, such that a pore protein deficient strain behaves as a K m mutant. Comparison of the rates of permeation of Pi, glycerol 3-phosphate and glucose 6-phosphate through pores formed by PhoE, OmpF and OmpC proteins shows that PhoE protein is the most effective pore in facilitating the diffusion of Pi and phosphorus-containing compounds. The three types of pores were about equally effective in facilitating the permeation of glucose and arsenate. Possible reasons for the preference for Pi and Pi-containing solutes are discussed.

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Major proteins of the outer cell envelope membrane ofEscherichia coli K-12: Multiple species of protein I

Cited by 86 publications

References 25 publications

Pore protein e of the outer membrane of escherichia coli K12

Pore protein e of the outer membrane of escherichia coli K12

Rate of Translation and Kinetics of Processing of Newly Synthesized Molecules of Two Major Outer‐Membrane Proteins, the OmpA and OmpF Proteins, of Escherichia coli K12

PhoE protein pore of the outer membrane of Escherichia coli K12 is a particularly efficient channel for organic and inorganic phosphate

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