RRC ID 47502
Author Iwasaki T, Kappl R, Bracic G, Shimizu N, Ohmori D, Kumasaka T.
Title ISC-like [2Fe-2S] ferredoxin (FdxB) dimer from Pseudomonas putida JCM 20004: structural and electron-nuclear double resonance characterization.
Journal J. Biol. Inorg. Chem.
Abstract The crystal structure of the ISC-like [2Fe-2S] ferredoxin (FdxB), probably involved in the de novo iron-sulfur cluster biosynthesis (ISC) system of Pseudomonas putida JCM 20004, was determined at 1.90-Å resolution and displayed a novel tail-to-tail dimeric form. P. putida FdxB lacks the consensus free cysteine usually present near the cluster of ISC-like ferredoxins, indicating its primarily electron transfer role in the iron-sulfur cluster. Orientation-selective electron-nuclear double resonance spectroscopic analysis of reduced FdxB in conjunction with the crystal structure has identified the innermost Fe2 site with a high positive spin population as the nonreducible iron retaining the Fe(3+) valence and the outermost Fe1 site as the reduced iron with a low negative spin density. The average g (max) direction is skewed, forming an angle of about 27.3° (±4°) with the normal of the [2Fe-2S] plane, whereas the g (int) and g (min) directions are distributed in the cluster plane, presumably tilted by the same angle with respect to this plane. These results are related to those for other [2Fe-2S] proteins in different electron transport chains (e.g. adrenodoxin) and suggest a significant distortion of the electronic structure of the reduced [2Fe-2S] cluster under the influence of the protein environment around each iron site in general.
Volume 16(6)
Pages 923-35
Published 2011-8
DOI 10.1007/s00775-011-0793-8
PMID 21647778
MeSH Amino Acid Sequence Bacterial Proteins / chemistry* Bacterial Proteins / metabolism Crystallography, X-Ray Electron Spin Resonance Spectroscopy / methods* Ferredoxins / chemistry* Ferredoxins / metabolism Models, Molecular Molecular Sequence Data Protein Conformation Protein Multimerization Pseudomonas putida / chemistry Pseudomonas putida / metabolism* Sequence Alignment
IF 3.632
Times Cited 9
General Microbes JCM 20004