| Content Provider |
World Health Organization (WHO)-Global Index Medicus |
| Author |
Dodd, Erin L. Al Bassam, Mahmoud M. Cramer, Stephen P. Thomson, Andrew J. Le Brun, Nick E. Crack, Jason C. Johnson, Michael K. Kamali, Saeed Knowles, Felicity Munnoch, John Holland, Ashley A. Hutchings, Matthew I. Hamilton, Chris J. |
| Description |
Author Affiliation: Crack JC ( From the Centre for Molecular and Structural Biochemistry, School of Chemistry.); Munnoch J ( the School of Biological Sciences, and.); Dodd EL ( From the Centre for Molecular and Structural Biochemistry, School of Chemistry.); Knowles F ( the School of Biological Sciences, and.); Al Bassam MM ( the School of Biological Sciences, and.); Kamali S ( the Department of Chemistry, University of California, Davis, California 95616, and.); Holland AA ( the Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602.); Cramer SP ( the Department of Chemistry, University of California, Davis, California 95616, and.); Hamilton CJ ( the School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom.); Johnson MK ( the Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602.); Thomson AJ ( From the Centre for Molecular and Structural Biochemistry, School of Chemistry.); Hutchings MI ( the School of Biological Sciences, and m.hutchings@uea.ac.uk.); Le Brun NE ( From the Centre for Molecular and Structural Biochemistry, School of Chemistry, n.le-brun@uea.ac.uk.) |
| Abstract |
The Rrf2 family transcription factor NsrR controls expression of genes in a wide range of bacteria in response to nitric oxide (NO). The precise form of the NO-sensing module of NsrR is the subject of controversy because NsrR proteins containing either [2Fe-2S] or [4Fe-4S] clusters have been observed previously. Optical, Mössbauer, resonance Raman spectroscopies and native mass spectrometry demonstrate that Streptomyces coelicolor NsrR (ScNsrR), previously reported to contain a [2Fe-2S] cluster, can be isolated containing a [4Fe-4S] cluster. ChIP-seq experiments indicated that the ScNsrR regulon is small, consisting of only hmpA1, hmpA2, and nsrR itself. The hmpA genes encode NO-detoxifying flavohemoglobins, indicating that ScNsrR has a specialized regulatory function focused on NO detoxification and is not a global regulator like some NsrR orthologues. EMSAs and DNase I footprinting showed that the [4Fe-4S] form of ScNsrR binds specifically and tightly to an 11-bp inverted repeat sequence in the promoter regions of the identified target genes and that DNA binding is abolished following reaction with NO. Resonance Raman data were consistent with cluster coordination by three Cys residues and one oxygen-containing residue, and analysis of ScNsrR variants suggested that highly conserved Glu-85 may be the fourth ligand. Finally, we demonstrate that some low molecular weight thiols, but importantly not physiologically relevant thiols, such as cysteine and an analogue of mycothiol, bind weakly to the [4Fe-4S] cluster, and exposure of this bound form to $O_{2}$ results in cluster conversion to the [2Fe-2S] form, which does not bind to DNA. These data help to account for the observation of [2Fe-2S] forms of NsrR. |
| ISSN |
00219258 |
| e-ISSN |
1083351X |
| Journal |
Journal of Biological Chemistry |
| Issue Number |
20 |
| Volume Number |
290 |
| Language |
English |
| Publisher |
American Society for Biochemistry and Molecular Biology (United States) |
| Publisher Date |
2015-05-15 |
| Publisher Place |
United States |
| Access Restriction |
Open |
| Subject Keyword |
Bacterial Proteins Metabolism DNA-Binding Proteins Iron-Sulfur Proteins Nitric Oxide Streptomyces Coelicolor Genetics Promoter Regions, Genetic Physiology Regulon Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Biochemistry Molecular Biology |
| Content Type |
Text |
| Resource Type |
Article |
| Subject |
Cell Biology Biochemistry Molecular Biology |
