Variability in the posttranslational processing of penicillin-binding protein 1b among different strains of Escherichia coli

1987 ◽  
Vol 65 (1) ◽  
pp. 62-67
Author(s):  
Fernando Rojo ◽  
José Berenguer ◽  
Juan A. Ayala ◽  
Miguel A. De Pedro
Keyword(s):  
Escherichia Coli ◽  
Binding Protein ◽  
Molecular Forms ◽  
Penicillin Binding Protein ◽  
E Coli ◽  
Form Processing ◽  
Different Strains ◽  
Cell Envelopes ◽  
Strain Dependent ◽  
Processing Mechanism

Screening of a number of unrelated strains of Escherichia coli confirms the existence of at least two patterns of molecular forms for penicillin-binding protein 1b in E. coli cell envelopes. Our data support that the β-form of this protein is produced by posttranslational modification of the α-form and suggest that the absence of the β-form in some strains is due to a strain-dependent variability in the α-form processing mechanism.

Deletion of the Penicillin-Binding Protein 6 Gene of Escherichia coli

1982 ◽  
Vol 152 (2) ◽  
pp. 904-906
Author(s):  
Jennifer K. Broome-Smith ◽  
Brian G. Spratt
Keyword(s):  
Escherichia Coli ◽  
Marked Effect ◽  
Binding Protein ◽  
Penicillin Binding Protein ◽  
E Coli

A strain of Escherichia coli with a deletion of the penicillin-binding protein 6 gene ( dacC ) has been constructed. The properties of this strain establish that the complete lack of penicillin-binding protein 6 has no marked effect on the growth of E. coli .

scholarly journals Overproduction of Penicillin-Binding Protein 2 and Its Inactive Variants Causes Morphological Changes and Lysis in Escherichia coli

2007 ◽  
Vol 189 (14) ◽  
pp. 4975-4983 ◽  
Author(s):  
Blaine A. Legaree ◽  
Calvin B. Adams ◽  
Anthony J. Clarke
Keyword(s):  
Escherichia Coli ◽  
Signal Sequence ◽  
Morphological Changes ◽  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Prolonged Incubation ◽  
Lytic Transglycosylases ◽  
E Coli ◽  
Derivatives Of

ABSTRACT Penicillin-binding protein 2 (PBP 2) has long been known to be essential for rod-shaped morphology in gram-negative bacteria, including Escherichia coli and Pseudomonas aeruginosa. In the course of earlier studies with P. aeruginosa PBP 2, we observed that E. coli was sensitive to the overexpression of its gene, pbpA. In this study, we examined E. coli overproducing both P. aeruginosa and E. coli PBP 2. Growth of cells entered a stationary phase soon after induction of gene expression, and cells began to lyse upon prolonged incubation. Concomitant with the growth retardation, cells were observed to have changed morphologically from typical rods into enlarged spheres. Inactive derivatives of the PBP 2s were engineered, involving site-specific replacement of their catalytic Ser residues with Ala in their transpeptidase module. Overproduction of these inactive PBPs resulted in identical effects. Likewise, overproduction of PBP 2 derivatives possessing only their N-terminal non-penicillin-binding module (i.e., lacking their C-terminal transpeptidase module) produced similar effects. However, E. coli overproducing engineered derivatives of PBP 2 lacking their noncleavable, N-terminal signal sequence and membrane anchor were found to grow and divide at the same rate as control cells. The morphological effects and lysis were also eliminated entirely when overproduction of PBP 2 and variants was conducted with E. coli MHD79, a strain lacking six lytic transglycosylases. A possible interaction between the N-terminal domain of PBP 2 and lytic transglycosylases in vivo through the formation of multienzyme complexes is discussed.

scholarly journals Affinity of Tomopenem (CS-023) for Penicillin-Binding Proteins in Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa

2008 ◽  
Vol 53 (3) ◽  
pp. 1238-1241 ◽  
Author(s):  
Tetsufumi Koga ◽  
Chika Sugihara ◽  
Masayo Kakuta ◽  
Nobuhisa Masuda ◽  
Eiko Namba ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Binding Proteins ◽  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
High Affinity

ABSTRACT Tomopenem (formerly CS-023), a novel 1β-methylcarbapenem, exhibited high affinity for penicillin-binding protein (PBP) 2 in Staphylococcus aureus, PBP 2 in Escherichia coli, and PBPs 2 and 3 in Pseudomonas aeruginosa, which are considered major lethal targets. Morphologically, tomopenem induced spherical forms in E. coli and short filamentation with bulges in P. aeruginosa, which correlated with the drug's PBP profiles. The potential of resistance of these bacteria to tomopenem was comparable to that to imipenem.

scholarly journals High-Throughput Screen for Inhibitors of Transglycosylase and/or Transpeptidase Activities of Escherichia coli Penicillin Binding Protein 1b

2004 ◽  
Vol 48 (1) ◽  
pp. 30-40 ◽  
Author(s):  
B. Chandrakala ◽  
Radha K. Shandil ◽  
Upasana Mehra ◽  
Sudha Ravishankar ◽  
Parvinder Kaur ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
Antibacterial Agents ◽  
Binding Protein ◽  
Type A ◽  
The Other ◽  
Penicillin Binding Protein ◽  
E Coli ◽  
Comparison Of The Results ◽  
High Throughput Assay

ABSTRACT Penicillin binding protein (PBP) 1b of Escherichia coli has both transglycosylase and transpeptidase activities, which are attractive targets for the discovery of new antibacterial agents. A high-throughput assay that detects inhibitors of the PBPs was described previously, but it cannot distinguish them from inhibitors of the MraY, MurG, and lipid pyrophosphorylase. We report on a method that distinguishes inhibitors of both activities of the PBPs from those of the other three enzymes. Radioactive peptidoglycan was synthesized by using E. coli membranes. Following termination of the reaction the products were analyzed in three ways. Wheat germ agglutinin (WGA)-coated scintillation proximity assay (SPA) beads were added to one set, and the same beads together with a detergent were added to a second set. Type A polyethylenimine-coated WGA-coated SPA beads were added to a third set. By comparison of the results of assays run in parallel under the first two conditions, inhibitors of the transpeptidase and transglycosylase could be distinguished from inhibitors of the other enzymes, as the inhibitors of the other enzymes showed similar inhibitory concentrations (IC50s) under both conditions but the inhibitors of the PBPs showed insignificant inhibition in the absence of detergent. Furthermore, comparison of the results of assays run under conditions two and three enabled the distinction of transpeptidase inhibitors. Penicillin and other β-lactams showed insignificant inhibition with type A beads compared with that shown with WGA-coated SPA beads plus detergent. However, inhibitors of the other four enzymes (tunicamycin, nisin, bacitracin, and moenomycin) showed similar IC50s under both conditions. We show that the main PBP being measured under these conditions is PBP 1b. This screen can be used to find novel transglycosylase or transpeptidase inhibitors.

Polyester Cloth–Based Hybridization Array System for Identification of Enterohemorrhagic Escherichia coli Serogroups O26, O45, O103, O111, O121, O145, and O157

2012 ◽  
Vol 75 (9) ◽  
pp. 1691-1697 ◽  
Author(s):  
BURTON W. BLAIS ◽  
MARTINE GAUTHIER ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI
Keyword(s):  
Escherichia Coli ◽  
Marker Gene ◽  
Enterohemorrhagic Escherichia Coli ◽  
Oligonucleotide Probes ◽  
E Coli ◽  
Polyester Cloth ◽  
Gene Profiles ◽  
Pcr Products ◽  
Different Strains ◽  
Immunoenzymatic Assay

A cloth-based hybridization array system (CHAS) was developed for the identification of foodborne colony isolates of seven priority enterohemorrhagic Escherichia coli (EHEC-7) serogroups targeted by U.S. food inspection programs. Gene sequences associated with intimin; Shiga-like toxins 1 and 2; and the antigenic markers O26, O45, O103, O111, O121, O145, and O157 were amplified in a multiplex PCR incorporating a digoxigenin label, and detected by hybridization of the PCR products with an array of specific oligonucleotide probes immobilized on a polyester cloth support, with subsequent immunoenzymatic assay of the captured amplicons. The EHEC-7 CHAS exhibited 100% inclusivity and 100% exclusivity characteristics with respect to detection of the various markers among 89 different E. coli strains, with various marker gene profiles and 15 different strains of non–E. coli bacteria.

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