Movatterモバイル変換

[0]ホーム
URL:

Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
Thehttps:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log inShow account info
Access keysNCBI HomepageMyNCBI HomepageMain ContentMain Navigation
pubmed logo
Advanced Clipboard
User Guide

Full text links

Elsevier Science full text link Elsevier Science Free PMC article
Full text links

Actions

Share

Comparative Study
.2011 Jan 7;405(1):173-84.
doi: 10.1016/j.jmb.2010.10.024. Epub 2010 Oct 23.

Crystal structures of penicillin-binding protein 3 from Pseudomonas aeruginosa: comparison of native and antibiotic-bound forms

Affiliations
Comparative Study

Crystal structures of penicillin-binding protein 3 from Pseudomonas aeruginosa: comparison of native and antibiotic-bound forms

Sarah Sainsbury et al. J Mol Biol..

Abstract

We report the first crystal structures of a penicillin-binding protein (PBP), PBP3, from Pseudomonas aeruginosa in native form and covalently linked to two important β-lactam antibiotics, carbenicillin and ceftazidime. Overall, the structures of apo and acyl complexes are very similar; however, variations in the orientation of the amino-terminal membrane-proximal domain relative to that of the carboxy-terminal transpeptidase domain indicate interdomain flexibility. Binding of either carbenicillin or ceftazidime to purified PBP3 increases the thermostability of the enzyme significantly and is associated with local conformational changes, which lead to a narrowing of the substrate-binding cleft. The orientations of the two β-lactams in the active site and the key interactions formed between the ligands and PBP3 are similar despite differences in the two drugs, indicating a degree of flexibility in the binding site. The conserved binding mode of β-lactam-based inhibitors appears to extend to other PBPs, as suggested by a comparison of the PBP3/ceftazidime complex and the Escherichia coli PBP1b/ceftoxamine complex. Since P. aeruginosa is an important human pathogen, the structural data reveal the mode of action of the frontline antibiotic ceftazidime at the molecular level. Improved drugs to combat infections by P. aeruginosa and related Gram-negative bacteria are sought and our study provides templates to assist that process and allows us to discuss new ways of inhibiting PBPs.

Copyright © 2010 Elsevier Ltd. All rights reserved.

PubMed Disclaimer

Figures

None
Graphical abstract
Fig. 1
Fig. 1
Thermal shift assay. (a) PBP3 screened with 500 μM carbenicillin, giving a ΔTm of + 13.2 °C. The blue curve is the native protein, and the red curve is the complex. (b) PBP3 screened with 500 μM ceftazidime, giving a ΔTm of + 14.5 °C. The blue curve is the native protein, and the black curve is the complex.
Fig. 2
Fig. 2
The overall structure of PBP3. (a) A ribbon diagram of the PBP3/carbenicillin complex showing the overall fold, antibiotic binding site, and bound glycerol. The diagram is rainbow-colored from blue at the N-terminus to red at the C-terminus, and the secondary structure elements are labelled in accordance with previous studies. (b–e) A comparison of the overall structure of native PBP3 (blue, orange, and red) with those of the PBP3/carbenicillin complex (b), PBP3/ceftazidime complex (c), PBP2 ofN. gonorrhoeae (d), and PBP2x fromS. pneumoniae (e). This figure was produced with PyMOL (www.pymol.org). The rest of the figures were drawn using BOBSCRIPT.
Fig. 3
Fig. 3
The active site of PBP3. (a–c) 2Fo − Fc maps calculated after the final round of refinement and contoured at 1σ showing the electron density for the three active site structural motifs in apo-PBP3, bound carbenicillin, and ceftazidime in the two complexes, respectively. In (b) and (c), the carbon atoms of the acylated S294 are shown in cyan. (d–f) The active sites of apo-PBP3, carbenicillin, and ceftazidime complexes. The protein main chains are shown as gray ribbons, side chains are drawn as cyan sticks, and the inhibitor is shown in orange ball-and-sticks. The red spheres represent water molecules, and the yellow broken lines represent potential hydrogen bonds. Residue V333 that makes contacts with the bound inhibitors is not shown in (e) and (f) for clarity. (g) Comparison of the active sites of the PBP3/carbenicillin complex (cyan) and the PBP3/ceftazidime complex (orange).
Fig. 4
Fig. 4
Glycerol binding, comparison with PBP1b, and electrostatic properties of the active site. (a) A diagram showing that the glycerol binding site is separated from the inhibitor binding site by β3–β4 strands and large conformational changes of the two strands due to inhibitor binding. The main-chain backbones of apo-PBP3 and the PBP3/carbenicillin complex are shown as gray and blue ribbons, respectively. (b) Comparison of the glycerol-binding site in the PBP3/carbenicillin complex with that in the apo-enzyme. The main chains and side chains are shown as ribbons and sticks, respectively (in gray and red for apo-PBP3; in blue and cyan for the carbenicillin complex), and the glycerol molecule is drawn as orange sticks. (c) Comparison of the active sites of the PBP3/ceftazidime complex (orange) and theS. pneumoniae PBP1b/cefotaxime complex (cyan). (d) Electrostatic surface showing the inhibitor-binding pocket of the PBP3/carbenicillin complex. (a) and (c) were produced with PyMOL (www.pymol.org).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Sauvage E., Kerff F., Terrak M., Ayala J.A., Charlier P. The penicillin-binding proteins: structure and role in peptidoglycan biosynthesis. FEMS Microbiol. Rev. 2008;32:234–258. - PubMed
    1. Zapun A., Contreras-Martel C., Vernet T. Penicillin-binding proteins and beta-lactam resistance. FEMS Microbiol. Rev. 2008;32:361–385. - PubMed
    1. Sung M.T., Lai Y.T., Huang C.Y., Chou L.Y., Shih H.W., Cheng W.C. Crystal structure of the membrane-bound bifunctional transglycosylase PBP1b from Escherichia coli. Proc. Natl Acad. Sci. USA. 2009;106:8824–8829. - PMC - PubMed
    1. Powell A.J., Tomberg J., Deacon A.M., Nicholas R.A., Davies C. Crystal structures of penicillin-binding protein 2 from penicillin-susceptible and -resistant strains of Neisseria gonorrhoeae reveal an unexpectedly subtle mechanism for antibiotic resistance. J. Biol. Chem. 2009;284:1202–1212. - PMC - PubMed
    1. Macheboeuf P., Di Guilmi A.M., Job V., Vernet T., Dideberg O., Dessen A. Active site restructuring regulates ligand recognition in class A penicillin-binding proteins. Proc. Natl Acad. Sci. USA. 2005;102:577–582. - PMC - PubMed

Publication types

MeSH terms

Substances

Associated data

Related information

Grants and funding

LinkOut - more resources

Full text links
Elsevier Science full text link Elsevier Science Free PMC article
Cite
Send To

NCBI Literature Resources

MeSHPMCBookshelfDisclaimer

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

[8]ページ先頭
©2009-2025 Movatter.jp