NMR analyses of the receiver domain of CKI1 histidine kinase and its interaction with AHP proteins
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| Year of publication | 2009 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | In a multistep phosphorelay, the C-terminal receiver domain of sensor histidine kinases is supposed to be involved in protein-protein interactions with its downstream signalling partners, the AHP proteins. Here we show that CKI1RD interacts in vivo and in vitro with AHP2, 3, and 5 with different affinities. To understand protein-protein interactions on the molecular level, the structure of CKI1RD in solution has been studied in details by nuclear magnetic resonance (NMR). Effects of magnesium ions (Mg2+) and phosphate analogue beryllium fluoride on chemical shift changes of CKI1RD have been studied in a series of titration experiments and the most significantly affected residues were identified. Observed chemical shift changes were mapped on a solved crystallographic structure of the protein. Molecular motions were investigated by NMR relaxation experiments with free, Mg2+-bound, and beryllofluorinated CKI1RD. Based on these data and in combination with bioinformatics approach, we determined four regions that might be responsible for the observed specificity of protein-protein interactions between CKI1RD and individual AHP proteins. |
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