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Solution structure of nickel-peptide deformylase
F Dardel1, S Ragusa, C Lazennec
1Unité Mixte de Recherche, Ecole Polytechnique, Palaiseau cedex, F-91128, France.
Journal of Molecular Biology
|July 17, 1998
Summary
Nickel, not zinc, activates peptide deformylase (PDF) enzyme activity. Structural analysis reveals nickel binding enhances enzyme function and identifies key active site residues, suggesting a common catalytic mechanism across proteases.
Area of Science:
- Biochemistry
- Structural Biology
- Enzymology
Background:
- Peptide deformylase (PDF) is crucial for protein synthesis.
- The role of metal co-factors in PDF activity was previously unclear.
- Previous structural studies of zinc-bound PDF showed inactivity.
Purpose of the Study:
- To investigate the role of nickel as a co-factor for PDF activity.
- To determine the 3D structure of nickel-bound PDF.
- To identify key active site residues and compare PDF structure to other proteases.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy on 13C-15N-labeled protein.
- X-ray crystallography (implied by comparison to previous structure).
- Site-directed mutagenesis.
Main Results:
- Nickel binding fully restores PDF hydrolytic activity, unlike zinc.
- High-resolution 3D structure of nickel-bound PDF determined.
- Structural comparison reveals conserved motifs and active site organization across different proteases (thermolysin, metzincins).
- Identified critical residues, including a buried arginine, essential for active site structure and function.
Conclusions:
- Nickel is the likely in vivo co-factor for active PDF.
- The bound metal ion is the primary determinant of PDF hydrolytic activity.
- PDF shares conserved structural features and potentially a common catalytic mechanism with other metalloproteases.