1dc7

Publication Abstract from PubMed

Receiver domains are the dominant molecular switches in bacterial signalling. Although several structures of non-phosphorylated receiver domains have been reported, a detailed structural understanding of the activation arising from phosphorylation has been impeded by the very short half-lives of the aspartylphosphate linkages. Here we present the first structure of a receiver domain in its active state, the phosphorylated receiver domain of the bacterial enhancer-binding protein NtrC (nitrogen regulatory protein C). Nuclear magnetic resonance spectra were taken during steady-state autophosphorylation/dephosphorylation, and three-dimensional spectra from multiple samples were combined. Phosphorylation induces a large conformational change involving a displacement of beta-strands 4 and 5 and alpha-helices 3 and 4 away from the active site, a register shift and an axial rotation in helix 4. This creates an exposed hydrophobic surface that is likely to transmit the signal to the transcriptional activation domain.

Structure of a transiently phosphorylated switch in bacterial signal transduction.,Kern D, Volkman BF, Luginbuhl P, Nohaile MJ, Kustu S, Wemmer DE Nature. 1999 Dec 23-30;402(6764):894-8. PMID:10622255^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.