Open AccessCleaved thioredoxin fusion protein enables the crystallization of poorly soluble ERα in complex with synthetic ligands
Author(s) -
Cura Vincent,
Gangloff Monique,
Eiler Sylvia,
Moras Dino,
Ruff Marc
Publication year - 2008
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107066444
Subject(s) - thioredoxin , fusion protein , crystallization , chemistry , fusion , solubility , cleavage (geology) , escherichia coli , ligand (biochemistry) , biochemistry , biophysics , peptide , nucleation , maltose binding protein , protein crystallization , crystallography , recombinant dna , biology , receptor , organic chemistry , paleontology , oxidative stress , linguistics , philosophy , fracture (geology) , gene
The ligand‐binding domain (LBD) of human oestrogen receptor α was produced in Escherichia coli as a cleavable thioredoxin (Trx) fusion in order to improve solubility. Crystallization trials with either cleaved and purified LBD or with the purified fusion protein both failed to produce crystals. In another attempt, Trx was not removed from the LBD after endoproteolytic cleavage and its presence promoted nucleation and subsequent crystal growth, which allowed the structure determination of two different LBD–ligand–coactivator peptide complexes at 2.3 Å resolution. This technique is likely to be applicable to other low‐solubility proteins.