Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 19, 2004
Previous Article Next Article

Sensing of remote oxyanion binding at the DNA binding domain of the molybdate-dependent transcriptional regulator, ModE

Author affiliations

Abstract

The molybdate-dependent transcriptional regulator ModE of Escherichia coli displays a large (50%) quenching of its intrinsic tryptophan fluorescence on binding molybdate. The changes in fluorescence have been exploited to analyse the binding of molybdate to ModE. Utilising site-directed mutagenesis, a series of phenylalanine substitutions for the three tryptophans of ModE (Trp49, Trp131 and Trp186) have been constructed, to yield three mono-Trp-containing derivatives. This has allowed an assessment to be made of the contribution of each of the three tryptophans to the spectral changes observed on binding molybdate; these are most distinctive for Trp186. Linkage between the DNA-binding and molybdate-binding sites (some 55 Å apart) is shown by (a) the small, but definite, effect of molybdate on the fluorescence of Trp49 which is located at the DNA-binding winged helix–turn–helix domain, and (b) the finding that the binding of either ligand is enhanced in the presence of the other. The studies demonstrate that the mono-Trp derivatives of ModE could be useful tools with which to study the signal transduction processes specifically associated with molybdate-dependent transcriptional regulation and that this approach may have wider implications for analysis of other regulated systems.

Graphical abstract: Sensing of remote oxyanion binding at the DNA binding domain of the molybdate-dependent transcriptional regulator, ModE

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 19 Mar 2004, accepted on 26 May 2004 and first published on 01 Sep 2004


Article type: Paper
DOI: 10.1039/B404185B
Citation: Org. Biomol. Chem., 2004,2, 2829-2837
  •   Request permissions

    Sensing of remote oxyanion binding at the DNA binding domain of the molybdate-dependent transcriptional regulator, ModE

    D. H. Boxer, H. Zhang, D. G. Gourley, W. N. Hunter, S. M. Kelly and N. C. Price, Org. Biomol. Chem., 2004, 2, 2829
    DOI: 10.1039/B404185B

Search articles by author