Backbone resonance assignment of the response regulator protein PhoBNF20D from Escherichia coli

Abstract

PhoB is a response regulator of the PhoR/PhoB two-component signal transduction system that is involved in the regulation of the phosphate (Pho) regulon of Escherichia coli. PhoB has two domains, receiver domain and effector domain. The receiver domain can be phosphorylated by its cognate histidine kinase PhoR and the phosphorylation induces conformational changes of the full length protein of PhoB that promote the DNA binding and transcription. Three-dimensional crystal structures of PhoB receiver domain (PhoB) have been solved under apo or BeF (a phosphoryl analog) binding forms and it has been found that PhoB is dimerized in both situations. However, we have found that the apo form of PhoB has multiple conformational changes in solution that is hard to be distinguished by using NMR spectroscopy, while the mutagenesis of F20D PhoB gives homogeneous dispersed signals in HSQC spectrum indicating a relatively uniform conformation. Meanwhile the F20D mutant has the same phosphorylation activity as the wild type protein. Here we report the backbone assignment of PhoB mutant. The chemical shift (HN, N, CO, C and C) analysis shows that the predicted regions of secondary structure are in good agreement with those observed in the crystal structure of apo PhoB. Therefore, the backbone chemical shifts assignment of PhoB mutant would be useful for studying the structure and dynamics of PhoB receiver domain and it has significance for explaining the mechanism of phosphorylation in TCSs.

A Novel Broad Host Range Phage Infecting Alteromonas

“…These two genes were previously found in other phages, including Vibrio phages, Roseobacter phages, and cyanophages [40,52]. G48 is annotated as the putative DNA-binding response regulator, PhoB, which functions as a two-component response regulator [53,54]. Phosphorylation of PhoB can enhance the affinity of DNA binding to regulate transcription in low-phosphate environments [53,54].…”

“…G48 is annotated as the putative DNA-binding response regulator, PhoB, which functions as a two-component response regulator [53,54]. Phosphorylation of PhoB can enhance the affinity of DNA binding to regulate transcription in low-phosphate environments [53,54]. The presence of phoB gene in the R8W genome implies potential adaptations to low-phosphate environments.…”

“…g19 encodes ThyX, a thymidylate synthase with two forms, ThyX and ThyA, which are primarily found in phages and bacteria, respectively. Thymidylate synthase can cata- DNA-binding response regulator, PhoB, which functions as a two-component response regulator [53,54]. Phosphorylation of PhoB can enhance the affinity of DNA binding to regulate transcription in low-phosphate environments [53,54].…”