3US6

Crystal Structure of Histidine-containing Phosphotransfer Protein MtHPt1 from Medicago truncatula


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.446 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.168 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Medicago truncatula histidine-containing phosphotransfer protein: Structural and biochemical insights into the cytokinin transduction pathway in plants.

Ruszkowski, M.Brzezinski, K.Jedrzejczak, R.Dauter, M.Dauter, Z.Sikorski, M.Jaskolski, M.

(2013) Febs J. 280: 3709-3720

  • DOI: 10.1111/febs.12363

  • PubMed Abstract: 
  • Histidine-containing phosphotransfer proteins (HPts) take part in hormone signal transduction in higher plants. The overall pathway of this process is reminiscent of the two-component system initially identified in prokaryotes. HPts function in histi ...

    Histidine-containing phosphotransfer proteins (HPts) take part in hormone signal transduction in higher plants. The overall pathway of this process is reminiscent of the two-component system initially identified in prokaryotes. HPts function in histidine-aspartate phosphorelays in which they mediate the signal from sensory kinases (usually membrane proteins) to RRs in the nucleus. Here, we report the crystal structure of an HPt protein from Medicago truncatula (MtHPt1) determined at 1.45 Å resolution and refined to an R-factor of 16.7% using low-temperature synchrotron-radiation X-ray diffraction data. There is one MtHPt1 molecule in the asymmetric unit of the crystal lattice with P2(1)2(1)2(1) symmetry. The protein fold consists of six α helices, four of which form a C-terminal helix bundle. The coiled-coil structure of the bundle is stabilized by a network of S-aromatic interactions involving highly conserved sulfur-containing residues. The structure reveals a solvent-exposed side chain of His79, which is the phosphorylation site, as demonstrated by autoradiography combined with site-directed mutation. It is surrounded by highly conserved residues present in all plant HPts. These residues form a putative docking interface for either the receiver domain of the sensory kinase, or for the RR. The biological activity of MtHPt1 was tested by autoradiography. It demonstrated phosphorylation by the intracellular kinase domain of the cytokinin receptor MtCRE1. Complex formation between MtHPt1 and the intracellular fragment of MtCRE1 was confirmed by thermophoresis, with a dissociation constant K(d) of 14 μM.


    Related Citations: 
    • The Arabidopsis histidine phosphotransfer proteins are redundant positive regulators of cytokinin signaling.
      Hutchison, C.E.,Li, J.,Argueso, C.,Gonzalez, M.,Lee, E.,Lewis, M.W.,Maxwell, B.B.,Perdue, T.D.,Schaller, G.E.,Alonso, J.M.,Ecker, J.R.,Kieber, J.J.
      (2006) Plant Cell 18: 3073
    • Crystal structure of the histidine-containing phosphotransfer protein ZmHP2 from maize.
      Sugawara, H.,Kawano, Y.,Hatakeyama, T.,Yamaya, T.,Kamiya, N.,Sakakibara, H.
      (2005) Protein Sci. 14: 202
    • Conservation of structure and function among histidine-containing phosphotransfer (HPt) domains as revealed by the crystal structure of YPD1.
      Xu, Q.,West, A.H.
      (1999) J.Mol.Biol. 292: 1039


    Organizational Affiliation

    Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Histidine-containing Phosphotransfer Protein type 1, MtHPt1
A
153Medicago truncatulaMutation(s): 0 
Gene Names: 11441941
Find proteins for B7FGU6 (Medicago truncatula)
Go to UniProtKB:  B7FGU6
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.446 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.168 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 38.554α = 90.00
b = 44.899β = 90.00
c = 85.905γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
MAR345data collection
PHENIXrefinement
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
XSCALEdata scaling
DENZOdata reduction
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-01-18
    Type: Initial release
  • Version 1.1: 2013-07-31
    Type: Database references
  • Version 1.2: 2017-11-08
    Type: Refinement description