PMID:9478932
| Citation |
Külzer, R, Pils, T, Kappl, R, Hüttermann, J and Knappe, J (1998) Reconstitution and characterization of the polynuclear iron-sulfur cluster in pyruvate formate-lyase-activating enzyme. Molecular properties of the holoenzyme form. J. Biol. Chem. 273:4897-903 |
|---|---|
| Abstract |
The glycyl radical (Gly-734) contained in the active form of pyruvate formate-lyase (PFL) of Escherichia coli is generated by the S-adenosylmethionine-dependent pyruvate formate-lyase-activating enzyme (PFL activase). A 5'-deoxyadenosyl radical intermediate produced by the activase has been suggested as the species that abstracts the pro-S hydrogen of the glycine 734 residue in PFL (Frey, M., Rothe, M., Wagner, A. F. V., and Knappe, J. (1994) J. Biol. Chem. 269, 12432-12437). To enable mechanistic investigations of this system we have worked out a convenient large scale preparation of functionally competent PFL activase from its apoform. The previously inferred metallic cofactor was identified as redox-interconvertible polynuclear iron-sulfur cluster, most probably of the [4Fe-4S] type, according to UV-visible and EPR spectroscopic information. Cys --> Ser replacements by site-directed mutagenesis determined Cys-29, Cys-33, and Cys-36 to be essential to yield active holoenzyme. Gel filtration chromatography showed a monomeric structure (28 kDa) for both the apoenzyme and holoenzyme form. The iron-sulfur cluster complement proved to be a prerequisite for effective binding of adenosylmethionine, which induces a characteristic shift of the EPR signal shape of the reduced enzyme form ([4Fe-4S]+) from axial to rhombic symmetry. |
| Links | |
| Keywords |
Amino Acid Sequence; Apoproteins/metabolism; Conserved Sequence; Cysteine/genetics; Electron Spin Resonance Spectroscopy; Enzyme Activation; Enzymes/biosynthesis; Enzymes/genetics; Escherichia coli/genetics; Iron/metabolism; Iron-Sulfur Proteins/biosynthesis; Iron-Sulfur Proteins/genetics; Ligands; Molecular Sequence Data; Mutagenesis, Site-Directed; Recombinant Proteins/biosynthesis; S-Adenosylhomocysteine/metabolism; S-Adenosylmethionine/metabolism; Spectrophotometry; Sulfides/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.