Azotobacter vinelandii ferredoxin I. Aspartate 15 facilitates proton transfer to the reduced [3Fe-4S] cluster.

Journal article

The [3Fe-4S]+/0 cluster of Azotobacter vinelandii ferredoxin I (AvFdI) has an unusually low and strongly pH-dependent reduction potential (E'0). The reduced cluster exists in two forms, depending upon pH, that exhibit substantially different magnetic circular dichroism (MCD) spectra. Recent studies have established that the MCD changes observed on decreasing the pH from 8.3 (alkaline form) to 6.0 (acid form) cannot be explained either by a change in spin state of the cluster (Stephens, P.J., ...

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Authors: Shen, B; Martin, L; Butt, J; Armstrong, F; Stout, C

• Publication status: Published
• Journal: Journal of biological chemistry
• Volume: 268
• Issue: 34
• Pages: 25928-25939
• Publication date: 1993-12-01
• EISSN: 1083-351X
• ISSN: 0021-9258
• Language: English
• Keywords: Mutagenesis, Site-Directed; Protein Conformation; Ferredoxins; Aspartic Acid; Azotobacter vinelandii; Hydrogen-Ion Concentration; Kinetics; Electron Spin Resonance Spectroscopy; Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Base Sequence; Amino Acid Sequence; Potentiometry; Circular Dichroism; Molecular Sequence Data; Genes, Bacterial; Models, Molecular; Oligodeoxyribonucleotides; Recombinant Proteins