PDBsum entry 3ehs

Membrane protein

PDB id: 3ehs

Contents

Protein chain

457 a.a. *

Ligands

GLC-GLC

Waters ×6

* Residue conservation analysis

PDB id:

3ehs

Name:

Membrane protein

Title:

Crystal structure of the extracellular domain of human corticotropin releasing factor receptor type 1 (crfr1)

Structure:

Fusion protein of crfr1 extracellular domain and mbp. Chain: a. Synonym: mmbp, maltodextrin-binding protein, crf-r, crf1, corticotropin-releasing hormone receptor 1, crh-r 1. Engineered: yes

Source:

Escherichia coli, homo sapiens. Organism_taxid: 83333, 9606. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.76Å R-factor: 0.209 R-free: 0.240

Authors:

A.A.Pioszak,H.E.Xu

Key ref:

A.A.Pioszak et al. (2008). Molecular Recognition of Corticotropin-releasing Factor by Its G-protein-coupled Receptor CRFR1. J Biol Chem, 283, 32900-32912. PubMed id: 18801728 DOI: 10.1074/jbc.M805749200

Date:

14-Sep-08 Release date: 30-Sep-08

Protein chain

P0AEX9  (MALE_ECOLI) -  Maltose/maltodextrin-binding periplasmic protein from Escherichia coli (strain K12)

Seq: 396 a.a.

Struc: 457 a.a.*

Protein chain

P34998  (CRFR1_HUMAN) -  Corticotropin-releasing factor receptor 1 from Homo sapiens

Seq: 415 a.a.

Struc: 457 a.a.*

* PDB and UniProt seqs differ at 26 residue positions (black crosses)

DOI no: 10.1074/jbc.M805749200

J Biol Chem 283:32900-32912 (2008)

PubMed id: 18801728

Molecular Recognition of Corticotropin-releasing Factor by Its G-protein-coupled Receptor CRFR1.

A.A.Pioszak, N.R.Parker, K.Suino-Powell, H.E.Xu.

ABSTRACT

The bimolecular interaction between corticotropin-releasing factor (CRF), a neuropeptide, and its type 1 receptor (CRFR1), a class B G-protein-coupled receptor (GPCR), is crucial for activation of the hypothalamic-pituitary-adrenal axis in response to stress, and has been a target of intense drug design for the treatment of anxiety, depression, and related disorders. As a class B GPCR, CRFR1 contains an N-terminal extracellular domain (ECD) that provides the primary ligand binding determinants. Here we present three crystal structures of the human CRFR1 ECD, one in a ligand-free form and two in distinct CRF-bound states. The CRFR1 ECD adopts the alpha-beta-betaalpha fold observed for other class B GPCR ECDs, but the N-terminal alpha-helix is significantly shorter and does not contact CRF. CRF adopts a continuous alpha-helix that docks in a hydrophobic surface of the ECD that is distinct from the peptide-binding site of other class B GPCRs, thereby providing a basis for the specificity of ligand recognition between CRFR1 and other class B GPCRs. The binding of CRF is accompanied by clamp-like conformational changes of two loops of the receptor that anchor the CRF C terminus, including the C-terminal amide group. These structural studies provide a molecular framework for understanding peptide binding and specificity by the CRF receptors as well as a template for designing potent and selective CRFR1 antagonists for therapeutic applications.

Selected figure(s)

Figure 4.
Structure of the CRF-(27-41)-NH[2]-bound CRFR1 ECD at 3.4 Å resolution. A, ribbon diagram of the crystal form III complex with the CRFR1 ECD colored slate blue and CRF yellow. MBP is not shown for clarity. B, electron density maps for CRF. The 2F[o] - F[c] omit map (blue) is contoured at 1 σ and the F[o] - F[c] omit map (green) is contoured at 3 σ. The maps were prepared as described under “Experimental Procedures.” C, detail of the interface depicted as in Fig. 3D. D, alignment of the crystal form II and form III structures. C-α backbone traces are shown with the CRF-(22-41)-NH[2]-bound ECD colored slate blue and CRF-(22-41)-NH[2] yellow. The CRF-(27-41)-NH[2]-bound ECD is colored blue and CRF-(27-41)-NH[2] sand.

Figure 7.
Comparison of the hCRFR1 ECD·CRF complex and the NMR solution structure of the mCRFR2β ECD·astressin complex. A-C, three views of a structural alignment of the crystal form II complex of CRF-(22-41)-NH[2] bound to the hCRFR1 ECD with the NMR solution structure of the mCRFR2β ECD bound to astressin (PDB code 2JND). C-α backbone traces are shown with the CRFR1 ECD·CRF complex colored slate blue and yellow, respectively, and the CRFR2β ECD·astressin complex colored cyan and red, respectively. D, molecular surface of the CRFR1 ECD from crystal form II colored according to sequence conservation between CRFR1 and CRFR2. The surface is colored light blue for residues that are identical, blue for residues that have conservative substitutions, and magenta for residues that differ between the two receptors. CRF-(22-41)-NH[2] is shown as a yellow coil. E, amino acid sequence alignment of the human CRFR1 ECD with the human and mouse CRFR2β ECDs. Secondary structure elements are shown at the top and the disulfide bond connectivity at the bottom. The color scheme is the same as in Fig. 3F.

The above figures are reprinted from an Open Access publication published by the ASBMB: J Biol Chem (2008, 283, 32900-32912) copyright 2008.

Figures were selected by an automated process.