1PUX: NMR Solution Structure of BeF3-Activated Spo0F, 20 conformers

Two-component systems, which are comprised of a single histidine-aspartate phosphotransfer module, are the dominant signaling pathways in bacteria and have recently been identified in several eukaryotic organisms as well. A tandem connection of two or more histidine-aspartate motifs forms complex phosphorelays. While response regulators from simple two-component systems have been characterized structurally in their inactive and active forms, we address here the question of whether a response regulator from a phosphorelay has a distinct structural basis of activation. We report the NMR solution structure of BeF(3)(-)-activated Spo0F, the first structure of a response regulator from a phosphorelay in its activated state. Conformational changes were found in regions previously identified to change in simple two-component systems. In addition, a downward shift by half a helical turn in helix 1, located on the opposite side of the common activation surface, was observed as a consequence of BeF(3)(-) activation. Conformational changes in helix 1 can be rationalized by the distinct function of phosphoryl transfer to the second histidine kinase, Spo0B, because helix 1 is known to interact directly with Spo0B and the phosphatase RapB. The identification of structural rearrangements in Spo0F supports the hypothesis of a pre-existing equilibrium between the inactive and active state prior to phosphorylation that was suggested on the basis of previous NMR dynamics studies on Spo0F. A shift of a pre-existing equilibrium is likely a general feature of response regulators.
PDB ID: 1PUXDownload
MMDB ID: 24114
PDB Deposition Date: 2003/6/25
Updated in MMDB: 2007/10
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Molecular Components in 1PUX
Label Count Molecule
Protein (1 molecule)
Sporulation Initiation Phosphotransferase F(Gene symbol: spo0F)
Molecule annotation
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Citing MMDB