The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
Gene Review

mrcB  -  penicillin-binding protein 1b

Escherichia coli O157:H7 str. EDL933

Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of mrcB

  • In this paper, we have analyzed the expression of ponB (mrcB), the structural gene for pbp 1b, and the relation among the three forms of pbp 1b in ponB strains lysogenyzed by lambda 540 (ponB+) recombinant bacteriophages [1].
  • We report that chlorobiphenyl vancomycin analogues that are incapable of binding substrates nevertheless inhibit E. coli PBP1b, which shows that these compounds interact directly with the enzyme [2].

High impact information on mrcB

  • We have identified transglycosylase assay conditions that enable kinetic analysis of inhibitors and have examined the inhibition of Escherichia coli penicillin-binding protein 1b (PBP1b) by moenomycin as well as by various glycopeptides [2].
  • We have also found that moenomycin is not competitive with respect to the lipid II substrate of PBP1b, as has long been believed [2].
  • These results strongly suggest that the periplasmic domain of PBP 1B associates with membranes independent of its amino terminal transmembrane region [3].
  • Twelve amino acids, comprised of the consensus thrombin cleavage site (LVPR decreases GS) and flanking glycine residues, were inserted into PBP 1B just past its putative transmembrane segment [3].
  • Cleavage of the protein was dependent upon the presence of the thrombin cleavage site, and the thrombin-cleaved protein (PBP 1Bper) displayed an identical affinity for [14C] penicillin G binding as wild-type PBP 1B and uncleaved PBP 1B-GT/H6 [3].

Chemical compound and disease context of mrcB


Biological context of mrcB

  • This paper reports the sequence of the active site peptide of penicillin-binding protein 1b from Escherichia coli [5].
  • Expression plasmids allowing the production of native PBP1B or of PBP1B variants with an inactive transpeptidase or transglycosylase domain or both were constructed [6].
  • Moreover, we have shown by alanine-stretch-scanning mutagenesis that (i) residues R(11) to G(13) are major determinants for correct translocation and folding of PBP1b and that (ii) the specific interactions involving the full-length PBP1b can be ascribed to the first six residues at the N-terminal end of the cytoplasmic domain [7].
  • The mutation, originally isolated in a strain with a high dosage of PBP1B, could also suppress the pbpB(Ts) phenotype when a single copy of the ponB gene was introduced [8].
  • The kinetics of the reaction of purified penicillin-binding protein 1b gamma from Escherichia coli with cephalosporins suggest that the enzyme exists in two kinetically distinct conformations that are in slow equilibrium [9].

Anatomical context of mrcB

  • These results indicated that PBP 1B of E. coli is compatible with the cytoplasmic membrane environment of unrelated bacterial species and support the idea that interspecific transfer of mutated alleles of genes coding for PBPs could potentially be an efficient spreading mechanism for intrinsic resistance to beta-lactams [4].

Associations of mrcB with chemical compounds


Analytical, diagnostic and therapeutic context of mrcB


  1. Analysis of the different molecular forms of penicillin-binding protein 1B in Escherichia coli ponB mutants lysogenized with specialized transducing lambda (ponB+) bacteriophages. Rojo, F., Ayala, J.A., De Pedro, M.A., Vázquez, D. Eur. J. Biochem. (1984) [Pubmed]
  2. Vancomycin analogues active against vanA-resistant strains inhibit bacterial transglycosylase without binding substrate. Chen, L., Walker, D., Sun, B., Hu, Y., Walker, S., Kahne, D. Proc. Natl. Acad. Sci. U.S.A. (2003) [Pubmed]
  3. Penicillin-binding protein 1B from Escherichia coli contains a membrane association site in addition to its transmembrane anchor. Nicholas, R.A., Lamson, D.R., Schultz, D.E. J. Biol. Chem. (1993) [Pubmed]
  4. Cloning and expression of the ponB gene, encoding penicillin-binding protein 1B of Escherichia coli, in heterologous systems. Plá, J., Rojo, F., de Pedro, M.A., Ayala, J.A. J. Bacteriol. (1990) [Pubmed]
  5. Purification and sequencing of the active site tryptic peptide from penicillin-binding protein 1b of Escherichia coli. Nicholas, R.A., Suzuki, H., Hirota, Y., Strominger, J.L. Biochemistry (1985) [Pubmed]
  6. Overproduction of inactive variants of the murein synthase PBP1B causes lysis in Escherichia coli. Meisel, U., Höltje, J.V., Vollmer, W. J. Bacteriol. (2003) [Pubmed]
  7. Differential responses of Escherichia coli cells expressing cytoplasmic domain mutants of penicillin-binding protein 1b after impairment of penicillin-binding proteins 1a and 3. Chalut, C., Charpentier, X., Remy, M.H., Masson, J.M. J. Bacteriol. (2001) [Pubmed]
  8. Identification of a new mutation in Escherichia coli that suppresses a pbpB (Ts) phenotype in the presence of penicillin-binding protein 1B. García del Portillo, F., de Pedro, M.A., Ayala, J.A. FEMS Microbiol. Lett. (1991) [Pubmed]
  9. The reaction of cephalosporins with penicillin-binding protein 1b gamma from Escherichia coli. Page, M.G. Biochim. Biophys. Acta (1994) [Pubmed]
  10. Moenomycin-mediated affinity purification of penicillin-binding protein 1b. Stembera, K., Buchynskyy, A., Vogel, S., Knoll, D., Osman, A.A., Ayala, J.A., Welzel, P. Chembiochem (2002) [Pubmed]
  11. Localization of penicillin-binding protein 1b in Escherichia coli: immunoelectron microscopy and immunotransfer studies. Bayer, M.H., Keck, W., Bayer, M.E. J. Bacteriol. (1990) [Pubmed]
  12. Topology of penicillin-binding protein 1b of Escherichia coli and topography of four antigenic determinants studied by immunocolabeling electron microscopy. den Blaauwen, T., Nanninga, N. J. Bacteriol. (1990) [Pubmed]
WikiGenes - Universities