Areas of Adhesion between Wall and Membrane of Escherichia coli

Bayer, Manfred

doi:10.1099/00221287-53-3-395

Cited by 323 publications

(159 citation statements)

References 21 publications

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“…10. Such contacts between the membranes, also called Bayer junctions, have long been known (46), although their existence has repeatedly been jeopardized (47). Consistent with our expectation PBP1B has been shown by the immune gold labeling technique to be present in membrane adhesion sites (48), and murein synthesizing activity has been found to be high in membrane fractions enriched in these zones of adhesion (49).…”

Section: Discussionsupporting

confidence: 77%

Demonstration of Molecular Interactions between the Murein Polymerase PBP1B, the Lytic Transglycosylase MltA, and the Scaffolding Protein MipA of Escherichia coli

Vollmer¹,

Rechenberg²,

Höltje

1999

Journal of Biological Chemistry

167

177

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Enlargement of the stress-bearing murein sacculus of bacteria depends on the coordinated interaction of murein synthases and hydrolases. To understand the mechanism of interaction of these two classes of proteins affinity chromatography and surface plasmon resonance (SPR) studies were performed. The membranebound lytic transglycosylase MltA when covalently linked to CNBr-activated Sepharose specifically retained the penicillin-binding proteins (PBPs) 1B, 1C, 2, and 3 from a crude Triton X-100 membrane extract of Escherichia coli. In the presence of periplasmic proteins also PBP1A was specifically bound. At least five different non-PBPs showed specificity for MltA-Sepharose. The amino-terminal amino acid sequence of one of these proteins could be obtained, and the corresponding gene was mapped at 40 min on the E. coli genome. This MltAinteracting protein, named MipA, in addition binds to PBP1B, a bifunctional murein transglycosylase/ transpeptidase. SPR studies with PBP1B immobilized to ampicillin-coated sensor chips showed an oligomerization of PBP1B that may indicate a dimerization. Simultaneous application of MipA and MltA onto a PBP1B sensor chip surface resulted in the formation of a trimeric complex. The dissociation constant was determined to be about 10 ؊6 M. The formation of a complex between a murein polymerase (PBP1B) and a murein hydrolase (MltA) in the presence of MipA represents a first step in a reconstitution of the hypothetical murein-synthesizing holoenzyme, postulated to be responsible for controlled growth of the stress-bearing sacculus of E. coli.The cell envelope of Gram-negative bacteria is stabilized by a thin, monolayered exoskeleton consisting of the cross-linked biopolymer murein (peptidoglycan) (1, 3). By forming a bagshaped structure the murein netting, glycan strands crosslinked by peptides, completely encloses the cell. Different models for the growth mechanism of this stress-bearing bacterial exoskeleton, called sacculus, have been put forward (2, 4, 5, 6). Despite the discrepancies in some details, the models all agree on one point, namely that murein synthases and hydrolases have to cooperate with each other to allow for safe insertion of new material into the growing sacculus. Specific protein-protein interactions between a number of enzymes involved in the metabolism of the murein sacculus have been demonstrated by affinity chromatography (7-8). This includes members of two opposing groups of enzyme specificities, murein polymerases (synthases) (9) and murein depolymerases (hydrolases) (10). The bifunctional murein transglycosylases/transpeptidases (11, 12), known as penicillin-binding proteins (PBPs) 1 1A, 1B and PBP1C, 2 and the transpeptidases PBP2 and PBP3 (13) as well as the endopeptidases PBP4 and PBP7 (14 -16) and the lytic transglycosylases Slt70, MltA, were found to interact with one another. These findings may reflect an in vivo assembly of murein synthases and murein hydrolases into a multienzyme complex that has been named a "yin yang complex" (3, 6). Such a murein ...

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Section: Discussionsupporting

confidence: 77%

Demonstration of Molecular Interactions between the Murein Polymerase PBP1B, the Lytic Transglycosylase MltA, and the Scaffolding Protein MipA of Escherichia coli

Vollmer¹,

Rechenberg²,

Höltje

1999

Journal of Biological Chemistry

167

177

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“…They have been called 'insertion points' and visualized in three different laboratories [35 -371. They might correspond to the sites of adhesion between inner and outer membrane [38]. According to Bayer 1371, who pointed out that E. coli rarely exhibits a tendency to cleave after freeze fracturing within the outer membrane, we postulate that the outer cell envelope does not strictly follow a lipid-bilayerprotein-mosaic model [39], specially at the insertion points.…”

Section: Discussionmentioning

confidence: 99%

“…), (B) then transferred by lateral diffusion to the outer membrane (O.M.) where the hydrophobic signal sequence becomes accessible to the protease, releasing it into the periplasm (P.) the adhesion sites previously described by Bayer [38] if they correspond to the hydrophobic channels. When the membrane is fluid, lateral diffusion and subsequent cleavage of hydrophobic tails would occur; this would ensure secretion without requiring significant energy other than the energy of protein synthesis.…”

Section: Discussionmentioning

confidence: 99%

Mechanistic Aspects of the Transfer of Nascent Periplasmic Proteins across the Cytoplasmic Membrane in Escherichia coli

Pagès

Piovant

Varenne

et al. 1978

European Journal of Biochemistry

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Spheroplasts, prepared according to an efficient procedure which is described, secrete a smaller protein fraction of the total cell content than that secreted by intact cells. However, more proteins are found associated to the cell envelopes derived from these spheroplasts than to those derived from intact cells.This result was confirmed when we measured, by specific immunoprecipitation, the amount of secreted and unsecreted alkaline phosphatase. Whereas at any time, at 30 "C, in intact cells 99.6 of the alkaline phosphatase produced is secreted and found in the periplasm [see A. Torriani (1968) J . Bacteviol. 96, 1200-12071, only 40% was secreted by our spheroplast preparation. We suggest that partial depletion of outer-membrane-bound protease (or proteases), involved in processing of precursors of secreted protein, is responsible for the significant defect of secretion of precursors which then remain membrane-bound. Such an experimental protocol has been carried out at various temperatures and the secretion of alkaline phosphatase was assayed. This secretion was found to slightly vary above 22 "C whereas it dramatically decreased below 22 "C. Practically no phosphatase was secreted at 13 "C. However, the synthesis of alkaline phosphatase was not differentially altered at low temperatures compared to total proteins. The inactive presumed precursor of this enzyme which was then not secreted was found associated to the cell envelope. Similar results have been observed in intact cells above 22 "C where only the energy of protein synthesis ( d E = 79 kJ), which causes the elongation of nascent chains, is used for protein secretion; below 22 "C, in the temperature range of the disorder-order transition of the lipid paraffin chains associated to membrane, a AE of 125 kJ is required for secretion of alkaline phosphatase. A A E of 146 kJ was found for this process to occur in the same temperature range in spheroplasts. When oleate was incorporated into the membrane of strain K 1059, an unsaturated fatty acid auxotroph, the same result as with wild-type strains was observed, but a decrease in secretion at high temperatures was induced by this modification of fatty acid composition of the membrane. When elaidate instead of oleate was incorporated into K1059 membrane, the fall in alkaline phosphatase secretion occurred at 33 "C instead of 22 "C, which indicates that the physical state of the lipid phase is really involved in the secretion process. A hypothetical model for secretion of nascent periplasmic proteins, based on the data reported, is presented.Many bacteria are known to secrete extracellular enzymes into the external medium. In gram-positive strains these proteins appear in the culture medium whereas in gram-negative strains the polypeptides are retained in a region located between the inner and outer membrane, which is called periplasmic space. Abbreviations. Hepes, 4-(2-hydroxyethyl)-l-piperazine-ethane-Enzymes. Alkaline phosphatase (EC 3.1.3.1); P-galactosidase Trivial Numes. Oleate, (Z)-9-octadecenoate; e...

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“…Burdett & Rogers (unpublished data) have found pegs in sections connecting the outer surface of the membrane with the cell wall. Areas of adhesions have been demonstrated between retracted cytoplasm and cell walls of Gram-negative bacteria (Bayer, 1968). There seems to be no doubt that the walls and membranes of bacteria are firmly pegged together.…”

Section: B J Veltri a N D J H Mcalearmentioning

confidence: 83%

Wall and Plasma Membrane Structures of Hydrogenomonas eutropha as Revealed by Stereography of Replicas from Complementary Freeze-etched Surfaces

Veltri

McAlear

1972

Journal of General Microbiology

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A method is described for fracturing frozen samples of Hydrogenomonas eutropha (HI 6 PHBA-4) so that both fracture faces can be studied by making platinum shadowed carbon replicas and locating complementary areas in each, employing the transmission electron microscope. Complementary areas studied by stereo microscopy showed complementary height differences in the corresponding replicas. Three pairs of complementary fracture faces had projections on the outermost faces of the inner layers of the plasma membranes which pulled out from the adjacent layer. Patches, bare of projections, on this surface had a complementary material of unknown function opposite.

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Areas of Adhesion between Wall and Membrane of Escherichia coli

Cited by 323 publications

References 21 publications

Demonstration of Molecular Interactions between the Murein Polymerase PBP1B, the Lytic Transglycosylase MltA, and the Scaffolding Protein MipA of Escherichia coli

Demonstration of Molecular Interactions between the Murein Polymerase PBP1B, the Lytic Transglycosylase MltA, and the Scaffolding Protein MipA of Escherichia coli

Mechanistic Aspects of the Transfer of Nascent Periplasmic Proteins across the Cytoplasmic Membrane in Escherichia coli

Wall and Plasma Membrane Structures of Hydrogenomonas eutropha as Revealed by Stereography of Replicas from Complementary Freeze-etched Surfaces

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