Experimental evidence of an alpha helix in Desulfovibrio desulfuricans Norway ferredoxin I: a two-dimensional NMR study.
Desulfovibrio ferredoxins are small proteins involved in biological oxido-reduction reactions and contain either one or two (4Fe-4S) clusters. The conformation of D. desulfuricans Norway ferredoxin I in solution was studied by two-dimensional NMR and various conformational parameters (n.O.e. and J-coupling) indicate the presence of an alpha-helix involving residues 41 to 50. These data confirm an earlier proposal (Fukuyama et al, J. Mol. Biol. 199, 183 (1988] in which the space of the missing cluster in monocluster ferredoxins is occupied by an alpha-helix. The evolutionary relevance of this result is discussed in view of published sequences and structures of related ferredoxins.
Marion
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Laboratory of Chemical Physics, N.I.D.D.K., Bethesda, MD 20892.
Guerlesquin
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D000595:Amino Acid Sequence; D003901:Desulfovibrio / Q000032:analysis*; D005288:Ferredoxins; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid
D005288:Ferredoxins