Conformational dynamics are a key factor in signaling mediated by the receiver domain of a sensor histidine kinase from Arabidopsis thaliana.

ABSTRACT: Multistep phosphorelay (MSP) cascades mediate responses to a wide spectrum of stimuli, including plant hormonal signaling, but several aspects of MSP await elucidation. Here, we provide first insight into the key step of MSP-mediated phosphotransfer in a eukaryotic system, the phosphorylation of the receiver domain of the histidine kinase CYTOKININ-INDEPENDENT 1 (CKI1_RD) from Arabidopsis thaliana We observed that the crystal structures of free, Mg²⁺-bound, and beryllofluoridated CKI1_RD (a stable analogue of the labile phosphorylated form) were identical and similar to the active state of receiver domains of bacterial response regulators. However, the three CKI1_RD variants exhibited different conformational dynamics in solution. NMR studies

SUBMITTER: Otrusinova O 

PROVIDER: S-EPMC5655527 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature