3US6

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

DOI: 10.2210/pdb3US6/pdb

Classification: TRANSFERASE
Organism(s): Medicago truncatula
Expression System: Escherichia coli
Mutation(s): No

Deposited: 2011-11-23 Released: 2012-01-18
Deposition Author(s): Ruszkowski, M., Brzezinski, K., Jedrzejczak, R., Dauter, M., Dauter, Z., Sikorski, M., Jaskolski, M.

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 1.45 Å
R-Value Free: 0.190
R-Value Work: 0.168
R-Value Observed: 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

PubMed: 23721763 Search on PubMedSearch on PubMed Central
DOI: 10.1111/febs.12363
Primary Citation of Related Structures:
3US6

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 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:

(by identity cutoff) | Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Histidine-containing Phosphotransfer Protein type 1, MtHPt1	A	153	Medicago truncatula	Mutation(s): 0 Gene Names: MtHPt, 11441941, MTR_2g020770, MtrunA17_Chr2g0286781 EC: 2.7.3
Find proteins for B7FGU6 (Medicago truncatula) Explore B7FGU6 Go to UniProtKB: B7FGU6
Protein Feature View Expand
Reference Sequence

Experimental Data & Validation

Experimental Data

Method: X-RAY DIFFRACTION
Resolution: 1.45 Å
R-Value Free: 0.190
R-Value Work: 0.168
R-Value Observed: 0.168
Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 38.554	α = 90
b = 44.899	β = 90
c = 85.905	γ = 90

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
PHASER	phasing
PHENIX	refinement
PDB_EXTRACT	data extraction
MAR345	data collection
XDS	data reduction
XSCALE	data scaling