The NMR solution structure of BeF(3)(-)-activated Spo0F reveals the conformational switch in a phosphorelay system.

Published

Journal Article

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.

Full Text

Duke Authors

Cited Authors

  • Gardino, AK; Volkman, BF; Cho, HS; Lee, S-Y; Wemmer, DE; Kern, D

Published Date

  • August 1, 2003

Published In

Volume / Issue

  • 331 / 1

Start / End Page

  • 245 - 254

PubMed ID

  • 12875849

Pubmed Central ID

  • 12875849

International Standard Serial Number (ISSN)

  • 0022-2836

Digital Object Identifier (DOI)

  • 10.1016/s0022-2836(03)00733-2

Language

  • eng

Conference Location

  • England