PDBsum entry 6dk5

Hormone

PDB id: 6dk5

Contents

Protein chains

21 a.a.

Waters ×24

PDB id:

6dk5

Name:

Hormone

Title:

The x-ray crystal structure of human endothelin-1, a polypeptide hormone regulator of blood pressure

Structure:

Endothelin-1. Chain: b, a. Fragment: unp residues 53-73. Synonym: preproendothelin-1,ppet1

Source:

Homo sapiens. Human. Organism_taxid: 9606

Resolution:

1.85Å R-factor: 0.208 R-free: 0.284

Authors:

A.Mcpherson

Key ref:

A.McPherson and S.B.Larson (2019). The X-ray crystal structure of human endothelin 1, a polypeptide hormone regulator of blood pressure. Acta Crystallogr F Struct Biol Commun, 75, 47-53. PubMed id: 30605125 DOI: 10.1107/S2053230X18016011

Date:

28-May-18 Release date: 02-Jan-19

Protein chains

P05305  (EDN1_HUMAN) -  Endothelin-1 from Homo sapiens

Seq: 212 a.a.

Struc: 21 a.a.

DOI no: 10.1107/S2053230X18016011

Acta Crystallogr F Struct Biol Commun 75:47-53 (2019)

PubMed id: 30605125

The X-ray crystal structure of human endothelin 1, a polypeptide hormone regulator of blood pressure.

A.McPherson, S.B.Larson.

ABSTRACT

Human endothelin is a 21-amino-acid polypeptide, constrained by two intra-chain disulfide bridges, that is made by endothelial cells. It is the most potent vasoconstrictor in the body and is crucially important in the regulation of blood pressure. It plays a major role in a host of medical conditions, including hypertension, diabetes, stroke and cancer. Endothelin was crystallized 28 years ago in the putative space group P6₁22, but the structure was never successfully solved by X-ray diffraction. Using X-ray diffraction data from 1992, the structure has now been solved. Assuming a unit cell belonging to space group P6₁ and a twin fraction of 0.28, a solution emerged with two, almost identical, closely associated molecules in the asymmetric unit. Although the data extended to beyond 1.8 Å resolution, a model containing 25 waters was refined to 1.85 Å resolution with an R of 0.216 and an R_free of 0.284. The disulfide-constrained `core' of the molecule, amino-acid residues 1-15, has a main-chain conformation that is essentially the same as endothelin when bound to its receptor, but many side-chain rotamers are different. The carboxy-terminal `tail' comprising amino-acid residues 16-21 is extended as when receptor-bound, but it exhibits a different conformation with respect to the `core'. The dimer that comprises the asymmetric unit is maintained almost exclusively by hydrophobic interactions and may be stable in an aqueous medium.