Document Detail

Dissection of hydrogen bond interaction network around an iron-sulfur cluster by site-specific isotope labeling of hyperthermophilic archaeal Rieske-type ferredoxin.
MedLine Citation:
PMID:  23145461     Owner:  NLM     Status:  MEDLINE    
The electronic structure and geometry of redox-active metal cofactors in proteins are tuned by the pattern of hydrogen bonding with the backbone peptide matrix. In this study we developed a method for selective amino acid labeling of a hyperthermophilic archaeal metalloprotein with engineered Escherichia coli auxotroph strains, and we applied this to resolve the hydrogen bond interactions with the reduced Rieske-type [2Fe-2S] cluster by two-dimensional pulsed electron spin resonance technique. Because deep electron spin-echo envelope modulation of two histidine (14)N(δ) ligands of the cluster decreased non-coordinating (15)N signal intensities via the cross-suppression effect, an inverse labeling strategy was employed in which (14)N amino acid-labeled archaeal Rieske-type ferredoxin samples were examined in an (15)N-protein background. This has directly identified Lys45 N(α) as providing the major pathway for the transfer of unpaired electron spin density from the reduced cluster by a "through-bond" mechanism. All other backbone peptide nitrogens interact more weakly with the reduced cluster. The extension of this approach will allow visualizing the three-dimensional landscape of preferred pathways for the transfer of unpaired spin density from a paramagnetic metal center onto the protein frame, and will discriminate specific interactions by a "through-bond" mechanism from interactions which are "through-space" in various metalloproteins.
Toshio Iwasaki; Risako Fukazawa; Yoshiharu Miyajima-Nakano; Amgalanbaatar Baldansuren; Shinichi Matsushita; Myat T Lin; Robert B Gennis; Kazuya Hasegawa; Takashi Kumasaka; Sergei A Dikanov
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2012-11-20
Journal Detail:
Title:  Journal of the American Chemical Society     Volume:  134     ISSN:  1520-5126     ISO Abbreviation:  J. Am. Chem. Soc.     Publication Date:  2012 Dec 
Date Detail:
Created Date:  2012-12-05     Completed Date:  2013-05-20     Revised Date:  2013-12-11    
Medline Journal Info:
Nlm Unique ID:  7503056     Medline TA:  J Am Chem Soc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  19731-8     Citation Subset:  IM    
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MeSH Terms
Binding Sites
Escherichia coli / genetics
Ferredoxins / chemistry*
Hydrogen Bonding
Iron / chemistry*
Isotope Labeling
Models, Molecular
Pyrodictiaceae / chemistry
Substrate Specificity
Sulfolobus solfataricus / chemistry
Sulfur / chemistry*
Grant Support
Reg. No./Substance:
0/Ferredoxins; 70FD1KFU70/Sulfur; E1UOL152H7/Iron

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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