NMR structure of the histidine kinase domain of the E. coli osmosensor EnvZ.
Bacteria live in capricious environments, in which they must continuously sense external conditions in order to adjust their shape, motility and physiology. The histidine-aspartate phosphorelay signal-transduction system (also known as the two-component system) is important in cellular adaptation to environmental changes in both prokaryotes and lower eukaryotes. In this system, protein histidine kinases function as sensors and signal transducers. The Escherichia coli osmosensor, EnvZ, is a transmembrane protein with histidine kinase activity in its cytoplasmic region. The cytoplasmic region contains two functional domains: domain A (residues 223-289) contains the conserved histidine residue (H243), a site of autophosphorylation as well as transphosphorylation to the conserved D55 residue of response regulator OmpR, whereas domain B (residues 290-450) encloses several highly conserved regions (G1, G2, F and N boxes) and is able to phosphorylate H243. Here we present the solution structure of domain B, the catalytic core of EnvZ. This core has a novel protein kinase structure, distinct from the serine/threonine/tyrosine kinase fold, with unanticipated similarities to both heatshock protein 90 and DNA gyrase B.
Tanaka
T
T
Center for Tsukuba Advanced Research Alliance and Institute of Applied Biochemistry, University of Tsukuba, Japan.
Saha
S K
SK
Tomomori
C
C
Ishima
R
R
Liu
D
D
Tong
K I
KI
Park
H
H
Dutta
R
R
Qin
L
L
Swindells
M B
MB
Yamazaki
T
T
Ono
A M
AM
Kainosho
M
M
Inouye
M
M
Ikura
M
M
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D000071677:Histidine Kinase; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D011487:Protein Conformation; D011494:Protein Kinases / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry
D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase; C057843:envZ protein, E coli