A Possible Role for Iron-Sulfur Cluster N2 in Proton Translocation by the NADH:Ubiquinone Oxidoreductase (Complex I)Flemming D.a · Stolpe S.a · Schneider D.a · Hellwig P.b · Friedrich T.a
aInstitut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität Freiburg, Freiburg, and bInstitut für Biophysik, Johann-Wolfgang-Goethe-Universität, Frankfurt am Main, Germany
Do you have an account?
- Rent for 48h to view
- Buy Cloud Access for unlimited viewing via different devices
- Synchronizing in the ReadCube Cloud
- Printing and saving restrictions apply
Rental: USD 8.50
Cloud: USD 20.00
Article / Publication Details
The proton-pumping NADH:ubiquinone oxidoreductase, the respiratory complex I, couples the transfer of electrons from NADH to ubiquinone with the translocation of protons across the membrane. The enzyme mechanism is still unknown due to the lack of a high-resolution structure and its complicated composition. The complex from Escherichia coli is made up of 13 subunits called NuoA through NuoN and contains one FMN and nine iron-sulfur (Fe/S) clusters as redox groups. The pH dependence of the midpoint redox potential of the Fe/S cluster named N2 and its spin-spin interaction with ubiquinone radicals made it an ideal candidate for a key component in redox-driven proton translocation. During the past years we have assigned the subunit localization of cluster N2 to subunit NuoB by site-directed mutagenesis and predicted its ligation by molecular simulation. Redox-induced FT-IR spectroscopy has shown that its redox reaction is accompanied by the protonation and deprotonation of individual amino acid residues. These residues have been identified by site-directed mutagenesis. The enzyme catalytic activity depends on the presence of cluster N2 and is coupled with major conformational changes. From these data a model for redox-induced conformation-driven proton translocation has been derived.
© 2005 S. Karger AG, Basel
Article / Publication Details
Copyright / Drug Dosage / DisclaimerCopyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.