1FRH

AZOTOBACTER VINELANDII FERREDOXIN I: ALTERATION OF INDIVIDUAL SURFACE CHARGES AND THE [4FE-4S] CLUSTER REDUCTION POTENTIAL

1FRH の概要

• エントリーDOI: 10.2210/pdb1frh/pdb
• 分子名称: FERREDOXIN, IRON/SULFUR CLUSTER, FE3-S4 CLUSTER, ... (4 entities in total)
• 機能のキーワード: electron transport
• 由来する生物種: Azotobacter vinelandii
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 12722.97

構造登録者

Stout, C.D. (登録日: 1993-09-27, 公開日: 1994-08-31, 最終更新日: 2024-02-07)

主引用文献

Shen, B.,Jollie, D.R.,Stout, C.D.,Diller, T.C.,Armstrong, F.A.,Gorst, C.M.,La Mar, G.N.,Stephens, P.J.,Burgess, B.K.
Azotobacter vinelandii ferredoxin I. Alteration of individual surface charges and the [4FE-4S]2+/+ cluster reduction potential.
J.Biol.Chem., 269:8564-8575, 1994

PubMed Abstract: The structures of Azotobacter vinelandii ferredoxin I (AvFdI) and Peptococcus aerogenes ferredoxin (PaFd), near their analogous [4e-4S]2+/+ clusters, are highly conserved (Backes, G., Mino, Y., Loehr, T.M., Meyer, T.E., Cusanovich, M.A., Sweeney, W.V., Adman, E.T., and Sanders-Loehr, J. (1991) J. Am. Chem. Soc. 11, 2055-2064). Despite these similarities, the reduction potential (E0') of the AvFdI [4Fe-4S]2+/+ cluster is more than 200 mV more negative than that of PaFd. We have tested the contribution that individual amino acid residues make to the control of E0' by converting residues in AvFdI into the corresponding residue in PaFd. Four mutations involved substitutions of negatively charged surface residues with neutral residues and two involved substitution of buried hydrophobic residues. All AvFdI variants were characterized by x-ray crystallography, absorption, CD, EPR, and 1H NMR spectroscopies and by electrochemical methods. For the F25I mutation, significant structural changes occurred that affected the EPR and 1H NMR spectroscopic properties of AvFdI and had a minor influence on E0'. For all other mutations there were no changes in reduction potential. Thus we conclude, that variations in charged surface residues do not account for the observed differences in E0' between the analogous [4Fe-4S]2+/+ cluster of PaFd and AvFdI. These differences are therefore most likely to be due to differences in solvent accessibility.

PubMed: 8132582

実験手法

X-RAY DIFFRACTION (2.3 Å)