1887

Abstract

VanD-type BM4339 is constitutively resistant to vancomycin and to low levels of teicoplanin. This strain produces peptidoglycan precursors terminating in D-lactate but, unlike VanA- and VanB-type strains, BM4339 has a mutated ligase gene and cannot synthesize D-Ala-D-Ala. Consequently, although it possesses and genes, it should not require an active VanX-type DD-dipeptidase or a VanY-type DD-carboxypeptidase for resistance. The gene contains the signatures of a penicillin-binding protein (PBP) and is believed to encode a penicillin-sensitive DD-carboxypeptidase. The enzyme activity was found to be membrane-bound and inhibited by low concentrations of benzylpenicillin in membrane preparations and in intact bacteria, indicating that the active site was present on the outside surface of the membrane. The 38 kDa protein was revealed as a PBP present in more copies per cell than conventional PBPs and all the protein was accessible to benzylpenicillin added externally, confirming the localization of the active site. A glycopeptide-susceptible strain of lacked this PBP, and the membrane-bound DD-carboxypeptidase activity was less than 5% of that of BM4339. Although the active site of VanY was external to the membrane, UDP-MurNAc-tetrapeptide was produced internally, probably from UDP-MurNAc-pentadepsipeptide. The presence of benzylpenicillin at low concentrations in the growth medium substantially reduced the amount of tetrapeptide produced, indicating that inhibition of VanY by benzylpenicillin influenced production of peptidoglycan precursors internally. A model to explain these contrasting observations is proposed.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-147-9-2571
2001-09-01
2019-10-19
Loading full text...

Full text loading...

/deliver/fulltext/micro/147/9/1472571a.html?itemId=/content/journal/micro/10.1099/00221287-147-9-2571&mimeType=html&fmt=ahah

References

  1. Arthur, M., Depardieu, F., Snaith, H. A., Reynolds, P. E. & Courvalin, P. ( 1994; ). Contribution of VanY dd-carboxypeptidase to glycopeptide resistance in Enterococcus faecalis by hydrolysis of peptidoglycan precursors. Antimicrob Agents Chemother 38, 1899-1903.[CrossRef]
    [Google Scholar]
  2. Arthur, M., Reynolds, P. & Courvalin, P. ( 1996; ). Glycopeptide resistance in enterococci. Trends Microbiol 4, 401-407.[CrossRef]
    [Google Scholar]
  3. Arthur, M., Depardieu, F., Cabanié, L., Reynolds, P. & Courvalin, P. ( 1998; ). Requirement of the VanY and VanX dd-peptidases for glycopeptide resistance in enterococci. Mol Microbiol 31, 819-830.
    [Google Scholar]
  4. Bugg, T. D. H., Wright, G. D., Dutka-Malen, S., Arthur, M., Courvalin, P. & Walsh, C. ( 1991; ). Molecular basis for vancomycin resistance in Enterococcus faecium BM4147: biosynthesis of a depsipeptide peptidoglycan precursor by vancomycin resistance proteins VanH and VanA. Biochemistry 30, 10408-10415.[CrossRef]
    [Google Scholar]
  5. Casadewall, B. & Courvalin, P. ( 1999; ). Characterization of the vanD glycopeptide resistance gene cluster from Enterococcus faecium BM4339. J Bacteriol 181, 3644-3648.
    [Google Scholar]
  6. Casadewall, B., Reynolds, P. & Courvalin, P. ( 2001; ). Studies of the regulation of expression of the vanD glycopeptide resistance gene cluster from Enterococcus faecium BM4339. J Bacteriol 183, 3436-3446.[CrossRef]
    [Google Scholar]
  7. Cooper, P. D. ( 1956; ). Site of action of radiopenicillin. Bacteriol Rev 20, 28-48.
    [Google Scholar]
  8. Gutmann, L., al-Obeid, S., Billot-Klein, D., Guerrier, M. L. & Collatz, E. ( 1994; ). Synergy and resistance to synergy between beta-lactam antibiotics and glycopeptides against glycopeptide-resistant strains of Enterococcus faecium. Antimicrob Agents Chemother 38, 824-829.[CrossRef]
    [Google Scholar]
  9. Joris, B., Ghuysen, J. M., Dive, G. & 8 other authors ( 1988; ). The active-site-serine penicillin-recognizing enzymes as members of the Streptomyces R61 dd-peptidase family. Biochem J 250, 313–324.
    [Google Scholar]
  10. Laemmli, U. K. ( 1970; ). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227, 680-685.[CrossRef]
    [Google Scholar]
  11. Messer, J. & Reynolds, P. E. ( 1992; ). Modified peptidoglycan precursors produced by glycopeptide-resistant enterococci. FEMS Microbiol Lett 94, 195-200.[CrossRef]
    [Google Scholar]
  12. Nagarajan, R. ( 1991; ). Antibacterial activities and modes of action of vancomycin and related glycopeptides. Antimicrob Agents Chemother 35, 605-609.[CrossRef]
    [Google Scholar]
  13. Périchon, B., Reynolds, P. & Courvalin, P. ( 1997; ). VanD-type glycopeptide-resistant Enterococcus faecium BM4339. Antimicrob Agents Chemother 41, 2016-2018.
    [Google Scholar]
  14. Périchon, B., Casadewall, B., Reynolds, P. & Courvalin, P. ( 2000; ). Glycopeptide-resistant Enterococcus faecium BM4416 is a VanD-type strain with an impaired d-alanine:d-alanine ligase. Antimicrob Agents Chemother 44, 1346-1348.[CrossRef]
    [Google Scholar]
  15. Rasmussen, J. R. & Strominger, J. L. ( 1978; ). Utilization of a depsipeptide substrate for trapping acyl-enzyme intermediates of penicillin-sensitive d-alanine carboxypeptidases. Proc Natl Acad Sci USA 75, 84-88.[CrossRef]
    [Google Scholar]
  16. Reynolds, P. E. ( 1989; ). Structure, biochemistry and mechanism of action of glycopeptide antibiotics. Eur J Clin Microbiol Infect Dis 8, 943-950.[CrossRef]
    [Google Scholar]
  17. Reynolds, P. E. ( 1998; ). Control of peptidoglycan synthesis in vancomycin-resistant enterococci: d,d-peptidases and d,d-carboxypeptidases. Cell Mol Life Sci 54, 325-331.[CrossRef]
    [Google Scholar]
  18. Reynolds, P. E., Arias, C. A. & Courvalin, P. ( 1999; ). Gene vanXY c encodes d,d-dipeptidase (VanX) and d,d-carboxypeptidase (VanY) activities in vancomycin-resistant Enterococcus gallinarum BM4174. Mol Microbiol 34, 341-349.[CrossRef]
    [Google Scholar]
  19. Somner, E. A. & Reynolds, P. E. ( 1990; ). Inhibition of peptidoglycan biosynthesis by ramoplanin. Antimicrob Agents Chemother 34, 413-419.[CrossRef]
    [Google Scholar]
  20. Wright, G. D., Molinas, C., Arthur, M., Courvalin, P. & Walsh, C. T. ( 1992; ). Characterization of VanY: a d,d-carboxypeptidase from vancomycin-resistant Enterococcus faecium BM4147. Antimicrob Agents Chemother 36, 1514-1518.[CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-147-9-2571
Loading
/content/journal/micro/10.1099/00221287-147-9-2571
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error