The functional and three-dimensional structural features of Cu,Zn superoxide dismutase coded by the Salmonella typhimurium sodCI gene, have been characterized. Measurements of the catalytic rate indicate that this enzyme is the most efficient superoxide dismutase analyzed so far, a feature that may be related to the exclusive association of the sodCI gene with the most pathogenic Salmonella serotypes. The enzyme active-site copper ion is highly accessible to external probes, as indicated by quenching of the water proton relaxation rate upon addition of iodide. The shape of the electron paramagnetic resonance spectrum is dependent on the frozen or liquid state of the enzyme solution, suggesting relative flexibility of the copper ion environment. The crystal structure (R-factor 22.6%, at 2.3 Angstrom resolution) indicates that the dimeric enzyme adopts the quaternary assembly typical of prokaryotic Cu,Zn superoxide dismutases. However, when compared to the structures of the homologous enzymes from Photobacterium leiognathi and Actinobacillus pleuropneumoniae, the subunit interface of Salmonella Cu,Zn superoxide dismutase shows substitution of 11 out of 19 interface residues. As a consequence, the network of structural water molecules that fill the dimer interface cavity is structured differently from the other dimeric bacterial enzymes. The crystallographic and functional characterization of this Salmonella Cu,Zn superoxide dismutase indicates that structural variability and catalytic efficiency are higher in prokaryotic than in the eukaryotic homologous enzymes. (C) 2000 Academic Press.

Pesce, A., Battistoni, A., Stroppolo, M., Polizio, F., Nardini, M., Kroll, J., et al. (2000). Functional and crystallographic characterization of Salmonella typhimurium Cu,Zn superoxide dismutase coded by the sodCI virulence gene. JOURNAL OF MOLECULAR BIOLOGY, 302(2), 465-478 [10.1006/jmbi.2000.4074].

Functional and crystallographic characterization of Salmonella typhimurium Cu,Zn superoxide dismutase coded by the sodCI virulence gene

BATTISTONI, ANDREA;POLIZIO, FRANCESCA;SETTE, MARCO;DESIDERI, ALESSANDRO;
2000-01-01

Abstract

The functional and three-dimensional structural features of Cu,Zn superoxide dismutase coded by the Salmonella typhimurium sodCI gene, have been characterized. Measurements of the catalytic rate indicate that this enzyme is the most efficient superoxide dismutase analyzed so far, a feature that may be related to the exclusive association of the sodCI gene with the most pathogenic Salmonella serotypes. The enzyme active-site copper ion is highly accessible to external probes, as indicated by quenching of the water proton relaxation rate upon addition of iodide. The shape of the electron paramagnetic resonance spectrum is dependent on the frozen or liquid state of the enzyme solution, suggesting relative flexibility of the copper ion environment. The crystal structure (R-factor 22.6%, at 2.3 Angstrom resolution) indicates that the dimeric enzyme adopts the quaternary assembly typical of prokaryotic Cu,Zn superoxide dismutases. However, when compared to the structures of the homologous enzymes from Photobacterium leiognathi and Actinobacillus pleuropneumoniae, the subunit interface of Salmonella Cu,Zn superoxide dismutase shows substitution of 11 out of 19 interface residues. As a consequence, the network of structural water molecules that fill the dimer interface cavity is structured differently from the other dimeric bacterial enzymes. The crystallographic and functional characterization of this Salmonella Cu,Zn superoxide dismutase indicates that structural variability and catalytic efficiency are higher in prokaryotic than in the eukaryotic homologous enzymes. (C) 2000 Academic Press.
2000
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/10 - BIOCHIMICA
English
Con Impact Factor ISI
Metalloproteins; Quaternary structure; Salmonella; Superoxide dismutase; Virulence factor
Pesce, A., Battistoni, A., Stroppolo, M., Polizio, F., Nardini, M., Kroll, J., et al. (2000). Functional and crystallographic characterization of Salmonella typhimurium Cu,Zn superoxide dismutase coded by the sodCI virulence gene. JOURNAL OF MOLECULAR BIOLOGY, 302(2), 465-478 [10.1006/jmbi.2000.4074].
Pesce, A; Battistoni, A; Stroppolo, M; Polizio, F; Nardini, M; Kroll, J; Langford, P; O'Neill, P; Sette, M; Desideri, A; Bolognesi, M
Articolo su rivista
File in questo prodotto:
File Dimensione Formato  
salmonella.pdf

solo utenti autorizzati

Licenza: Creative commons
Dimensione 518.62 kB
Formato Adobe PDF
518.62 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

Questo articolo è pubblicato sotto una Licenza Licenza Creative Commons Creative Commons

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/55077
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact