Abstract
Heme nitric oxide/oxygen (H-NOX) proteins are found in eukaryotes where they are typically part of a larger protein such as soluble guanylate cyclase and in prokaryotes where they are often found in operons with a histidine kinase, suggesting that H-NOX proteins serve as sensors for NO and O2 in signaling pathways. The Fe(II)-NO complex of the H-NOX protein from Shewanella oneidensis inhibits the autophosphorylation of the operon-associated histidine kinase, whereas the ligand-free H-NOX has no effect on the kinase. NMR spectroscopy was used to determine the structures of the Fe(II)-CO complex of the S. oneidensis H-NOX and the Fe(II)-CO complex of the H103G H-NOX mutant as a mimic of the ligand-free and kinase-inhibitory Fe(II)-NO H-NOX, respectively. The results provide a molecular glimpse into the ligand-induced conformational changes that may underlie kinase inhibition and the subsequent control of down-stream signaling.
Original language | English (US) |
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Pages (from-to) | 19753-19760 |
Number of pages | 8 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 106 |
Issue number | 47 |
DOIs | |
State | Published - Nov 24 2009 |
Externally published | Yes |
Keywords
- Hemoprotein
- NMR
- Nitric oxide
- Phosphorylation
- Signaling